HCI researchers looked into applying blockchain ecosystems for social sharing. Recent work of Elsden et al. [2018] offers a typology of blockchain-based applications, including crowdfunding, payment services, voting, copyright management, supply-chain tracking, authentication services, and distributed organizations. They emphasized that all of these applications have to deal with issues of establishing online identity, managing online privacy, and peer-to-peer online collaboration [Elsden et al., 2018]. Pazaitis et al. [2017] specifically explored the potential of blockchain technologies in the context of the sharing economy and detailed the concept of value creation in peer-review and peer-evaluation systems. They have also argued for the importance of maintaining human interactions in "trustless" blockchain ecosystems, especially in the context of sharing personal resources and assets. Drawing on their recommendation, in our JSI smartphone application, we instruct the peers to enter their contact details (e.g., a phone number, an email or an instant messaging handle) in order to get in contact with each other to arrange necessary details of a transaction, for example to reach an agreement about an item's delivery and return.

#### **6.3.1 Motivating Scenario**

We offer a prototypical scenario (see Figure 6.7) to better contextualize the envisioned application of JSI. A potential lender (Alice) is interested in making some extra money from her infrequently used high-end ski-touring gear. She thus creates a listing in a local sharing economy service. Bob responds to the ad, gets in touch with Alice, borrows the equipment (Figure 6.7a), and eventually goes on a ski-touring trip. During his trip, he damages the gear on rocky terrain (Figure 6.7b). Once Bob returns the gear, Alice asks Bob to pay for the damages. While Alice's insurance will not pay, as the skis were rented out, Bob finds out that his insurance does not pay, as he opted out of the "gross negligence option" in his premium (Figure 6.7c). In the end, Bob agrees to pay half of the amount

*Figure 6.7.* A motivating scenario of sharing personal possessions. Icons by Sergey Demushkin, Vaibhav Radhakrishnan, Marc Serre, Andrew Doane, Icon Fair from the Noun Project

Alice asked for. Both remain unhappy with the overall transaction. We envision that JSI can improve the overall satisfaction from this prototypical transaction by implementing a reputation review mechanism into a platform's design, and by reducing the amount of intermediaries through leveraging an escrow property of smart contracts (see e.g., [Elsden et al., 2019]).

#### **6.3.2 JSI Ecosystem**

JSI is a software ecosystem to support the efficient sharing of personal physical objects. It is comprised of three components:

#### **Mobile Application**

The smartphone app allows lenders to create personal inventories of items they would like to lend. A lender can assign a name, a category and an item description, and set a security deposit and optional period-based price (Figure 6.8a). A borrower can search for an item in his or her vicinity (Figure 6.8b) and subsequently

*Figure 6.8.* (a) A lender's view of an item. (b) A borrower's search result. (c) A review left to a borrower after a transaction is completed.

make a request to borrow it. The lender can look at a social profile of a borrower and her previous transactions, and then accept or reject the request. In the current iteration of the prototype, we did not provide a private messaging functionality within the app, but rather rely on existing services such as WhatsApp, E-mail, or simply a phone call for parties to come to an agreement (e.g., to arrange an item's pickup/delivery and return) – in-app messaging could obviously be trivially integrated into a future version. Our mobile application was in part inspired by our Roaming Objects system (see Section 6.2.2), a tool-sharing platform that provides an online presence to everyday objects by augmenting them with the borrowers' personal experiences in the form of user-generated reports/reviews. Drawing on Roaming Object's design strategy (i.e. digital histories of use), we incorporated and extended it into the reputation review mechanism of the JSI app. Lenders and borrowers can rate their overall experience of interaction with each other in the form of images, ratings, and textual descriptions (Figure 6.8c). The purpose is twofold: borrowers provide histories of use for a given shared object, while lenders can report whether the object was returned in good condition. If needed, the app implements a dispute resolution mechanism to resolve potential transaction conflicts (see the Trust Model section). JSI uses the Web3 JavaScript framework to interact with blockchain smart contracts, which we explain in more detail below.

#### **Blockchain Smart Contracts**

JSI uses two types of smart contracts: *transaction* smart contracts (TSC) and *rating* smart contracts (RSC). A TSC models the state of a transaction from the

moment a borrower's request is accepted by a lender, to the moment when the shared item is returned. When a lender accepts a borrowing request, a new TSC is created containing both numerical identities of lender and borrower, as well that of the requested item. At this stage, the security deposit and the usage fee, as specified by the lender, are automatically transferred from the borrower's account to the TSC. Note that we use an external service (www.coinmarketcap.com) to automatically convert all fees from a user's base currency (e.g., Swiss Francs) to Ether cryptocurrency. Once the sharing period is over and the item is returned, the lender can request to terminate the TSC. At this point, the item usage fee will be transferred from the TSC to the lender's account. In case of a damaged or non-returned item, a lender can also request the security deposit that is "stored" in the TSC. All payments require a 2-out-of-3 multi-party agreement. Typically, both the lender and the borrower agree and hence can trigger the payout or payback. However, in the case of a disagreement, a trusted third-party can break the tie and decide on who receives the fee and/or deposit, thus terminating the TSC. Until then, all fees are locked in the TSC.

After terminating a TSC, both lender and borrower may rate each other's services regarding the shared item. Rating results are kept in users' individual RSCs, which are created as a part of users' registration. To minimize blockchain processing overhead (and minimize transaction execution costs), we combine blockchain-based RSCs with off-chain storage. Detailed rating data (textual and image-based reviews) are stored in an off-chain database, while a single rating score (i.e., an average) is committed to the user's RSC. To ensure the integrity of the detailed rating data, its fingerprint (computed using a hash function) is also committed in the user's RSC. Each RSC has a built-in access control mechanism which prevents users to rate themselves or to rate a fictitious sharing experience (i.e., "fake reviews"), but also to retrospectively modify their historical ratings.

We designed both TCS and RCS using Solidity, a contract-oriented programming language. We deploy contracts to an Ethereum blockchain testnet through Infura – a service provider for Ethereum infrastructure (see Permissioned vs Open Blockchains section for reflections on "in the wild" deployment opportunities).

#### **Backend Server**

The backend server administers inventory, storage and retrieval of the shared items for each user, and handles its profile data. It is implemented using JavaScriptbased frameworks (Node.js and Express.js) and a non-relational database (MongoDB) to enable robust deployment and scaling. The server can be accessed using

a RESTful API. As in the mobile client, we use the Web3 framework to manage smart contract interaction at the server side. The backend uses a push notification mechanism to inform users throughout the transaction stages (accepted, rejected, returned, in-dispute).

#### **6.3.3 Trust Model**

Trust in JSI comes from two factors. Firstly, each user has a (pseudo-)identity (e.g., picture, name, location) as opposed to the completely anonymous alphanumeric identities used in many other blockchain applications (i.e., Bitcoin). Secondly, reputation scores and reviews allow peers to build-up a reputation, thus allowing others to assess their perceived level of trust prior to engaging in a sharing transaction.

Obviously, this is far from guaranteeing conflict-free sharing experiences. A malicious lender could fail to deliver an item after accepting a borrowing request and then claim for compensation of her allegedly lost item, or incorrectly report that a returned item was damaged by the borrower. A dishonest borrower may equally refuse to pay the security deposit for an item he or she broke. JSI thus relies on "multi-party" smart contracting to resolve such disputes. In case of a disagreement between the lender and the borrower, a trusted third-party is needed to resolve the dispute by deciding who gets how much of the already pre-paid fees for the disputed transaction. The assigned intermediary can listen to both parties and inspect any system logs for evidence. Note that, however, a detailed description of how one can resolve a dispute is outside the scope of this work. This marks a salient opportunity for future research.

Ultimately, we imagine that the role of this trusted third-party would be delegated to the borrowed things themselves. In an IoT-enabled future, a "smart thing" would feature sensing, computing, and communication capabilities, allowing it to detect its own state throughout its use (Figure 6.9). Should a dispute between the involved peers arise, the smart contract would then resolve any disagreement based on evidence from the actual borrowed object. While such a solution would effectively remove any intermediaries from the system, it would need to carefully assess (and address) any vulnerabilities of a malicious peer bypassing an item's self-sensing system.

#### **6.3.4 Permissioned vs Open Blockchains**

The original blockchain model (e.g., Bitcoin and Ethereum) is "open" – anyone can join the network and participate in the consensus-building process when

Sign a digital smart contract to automate clearing and security deposit

Owner or even IoT skis can trigger the execution of the smart contract to acquire the security deposit fee

*Figure 6.9.* Future scenario, where the lender (Alice) provides the GPS-enabled ski-touring gear with a trusted platform module to the borrower (Bob), and eventually executes smart contract once received damaged equipment back. Icons by Sergey Demushkin, Vaibhav Radhakrishnan, Chameleon Design from the Noun Project

executing a transaction (i.e., appending a new data block, creating new smart contracts, or editing existing ones). This model is known as a "permissionless" (or public) blockchain. In this model, network participants do not trust each other, and they are not required to reveal their true identity. However, they rely on a computationally expensive protocol ("Proof-of-Work") to achieve consensus in order to maintain the integrity of the chain and to build up trust.

Contrary to this, there is the "permissioned" (or private) blockchain, which restricts who can join the network and who can participate in the transaction execution process. Here, new transactions are validated by a subset of recognized entities, resulting in a more efficient consensus-building protocol. However, this model assumes that there exists some level of initial trust among network participants.

In both versions, performing a blockchain operation requires a user to pay a monetary fee. In the permissionless version, this fee acts as an incentive for network participants to validate a transaction: the lower the fee, the longer it will take for "the blockchain" (i.e., the community of participants) to commit a transaction to the ledger. As a consequence, the amount of money paid by peers for their transaction directly influences how quickly their contract would be executed.

Conversely, in the permissioned model, transactions are executed only by a recognized set of participants (and/or by the blockchain infrastructure provider). As a result, one can agree at the beginning on a fixed execution cost for all

future transactions (e.g., by means of contractual agreement with the blockchain provider), removing the need for an incentive-setting pricing model. This would ensure constant transaction execution times and potentially reflect positively on the overall user experience with JSI.

In summary, depending on which blockchain model we select (permissionless vs. permissioned), there are several factors that can potentially impact a user's experience with our system. Among such affected factors are: 1) user waiting times before an operation can be committed to the blockchain, 2) the initial trust level towards those that ensure ledger's integrity, and 3) the level of active user involvement (i.e., cognitive load) when dealing with blockchain-based operations.

#### **6.3.5 A proposition for a Future Work**

In this section, we outline the rationale, the prototypical scenario, and the architecture of the "Just Share It" (JSI) application. The JSI client runs on a mobile platform and incorporates both blockchain and smart contracting technologies (using Ethereum, an open-source distributed computing platform). In a permissioned blockchain setting, JSI may offer reasonable costs and usability. On the whole, transparency of sharing transactions and integrity of the peer reviews as design strategies can be valuable for establishing trust within a sharing service at hand.

In our view, the natural unfolding of this work would be a field deployment of JSI within an existing online sharing community (e.g., Peerby, Sharely). This will not only allow future research to elicit aspects of perceived trust within a sharing platform and to examine the role of blockchain technologies in trust accrual, but also identify challenges and opportunities related to the actual use of emerging blockchain-based ecosystems in the sharing economy services. In particular, we see the value in raising the following two questions for the HCI community: "What are the users' perceptions of trust enabled by the smart contracting technologies within a sharing economy community?" and "How blockchain-based technology interventions can facilitate or inhibit trust within a community and within a supporting platform?" Ultimately, we hope this work inspires future research into how blockchain-based technologies can further support physical sharing practices in an IoT future, where everyday things are controlled by a machine agent, and thus have their own decision-making capabilities and power to execute smart contracts.

#### **6.4 Summary**

This chapter contributed to our research goal **G2** that is *to describe nuanced design characteristics for interactive technologies to support physical sharing practices in the context of the sharing economy*. We conducted two empirical studies to achieve this goal. The first one examined the physical sharing practices of individuals, the second one – of a resource sharing community.

At the outset, we recruited 71 participants and examined their individual sharing practices of everyday purchases. We identified the most shared categories of purchases, namely purchases related to "home" expenditures (e.g., groceries) as well as to "experiences" (e.g., trips, events). We subsequently determined that sharing purchases typically takes place with close family members and friends. We also computationally identified that overall perceived purchase satisfaction positively affects its sharing. Looking further into the relationship among satisfaction from a purchase and its sharing we elicited the motivational and experiential aspects of sharing everyday purchases. We outlined seven categories of motivational factors spanning social, hedonic, eudaimonic and environmental aspects of everyday consumption. We then reflected how selected factors can be used in user experience design of future persuasive technologies that support purchase sharing.

Next, we established a case study with the Vancouver Tool Library, a tool sharing cooperative, to examine sharing practices of their community members. At this stage, we identified three emergent challenges of the tool-sharing community: (1) the large degree of members' anonymity, (2) poor visibility of members' work, and (3) the lack of accountability for shared resources. We hypothesized that those challenges can be partially addressed through capturing and sharing members' tool-use experiences. For this purpose, we designed and developed the Roaming Objects mobile application. We subsequently field-tested and deployed the application at the VTL for eight weeks. We additionally conducted a series of follow-up interviews with 16 members to reflect on their experience with Roaming Objects. Through encoding and sharing digital histories of tool-use, Roaming Objects elicited a range of self-reflections across members of the VTL – from contemplations on personal relations and uses of tools, to speculations about shared tools themselves and their value on a broader community-level over time. Drawing on these insights, we synthesized a set of design recommendations for resource sharing cooperatives and collectives to attend to three aforementioned challenges. Firstly, we demonstrated the added-value of the progressive self-disclosure design technique – the gradual revealing of one's identity or individual information in relation to a shared resource. Roaming Objects allowed the VTL members to create

personal profiles with various levels of social disclosure to mitigate their privacy concerns. Thus, this technique has potential in *de-anonymizing* the community membership, and enable and a stronger sense of shared practices, values and intimacy between the tool library members and the community as a whole to emerge overtime. Secondly, recording and archiving experiential histories of use enabled members to gain valuable glimpses into the largely unseen practices of how tools were being applied in a range of members' respective everyday projects outside of the site of the tool library. Thus, the digital histories of use *increased visibility* of members' practices. Thirdly, accrued digital histories of use became useful indicators for the volunteers of the tool library to ensure up-to-date and detailed inventories, timely maintenance and repair of the tools. This decision led to an increased overall *accountability* of the tools among volunteers and members. It also better supported decision-making processes among members in terms of choosing the appropriate tool for a job. Lastly, we illustrated that Roaming Objects supported creating dynamic thing-story assemblages that can and will change over time and acquire new narratives as physical things change many hands. We consequently discussed the opportunities for expanding those assemblages across multiple devices and contexts beyond tool-sharing communities.

Building upon these insights, we looked beyond local resource sharing communities and explored the context of "informal" economies of personal artifacts. Prior research identified that contemporary online sharing platforms face several challenges related to the establishment of trust among peers, as well difficulties to deal with the growing number of intermediaries (e.g., payment, insurance) needed to ensure an adequate service delivery and accountability for shared resources. To approach these challenges we designed and developed "Just Share It", an interactive system that enables the sharing of personal physical possessions (e.g., power tools, toys, sports gear) by directly connecting lenders and borrowers, as peers, through mobile technology. The JSI system utilizes a blockchain ledger and smart contracting technologies to improve peer trust and limit the number of required intermediaries respectively. We argued that transparency of transactions and immutability of storage afforded by blockchain ecosystems could be seen as valuable design resources to ensure the integrity of reputation review mechanisms. Ultimately, we reflected on prospective architectural challenges and outlined opportunities for designers of future technology-mediated sharing practices that look into incorporating emergent blockchain technologies in their design concepts.

Collectively, this chapter developed the design sensibilities and outlined specific design strategies for interactive technologies to support physical sharing practices in the context of the sharing economy. In particular, we discussed the UX

design opportunities to support individuals in sharing everyday purchases. We also demonstrated how the digital histories of use as a design strategy can attend to the interpersonal and organizational challenges of resource sharing communities. Finally, we offered a design intervention employing nascent smart contracting technologies to approach the emergent issues of trust, disintermediation, and accountability within informal economies of personal artifacts. Drawing on the findings described in this chapter, in the next chapter, we specifically inquire how designers of sharing economy services can adopt this design research knowledge in order to improve existing platforms, as well as to devise new value-added services in the context of the sharing economy.

## **Chapter 7**

## **Supporting Designers in the Context of the Sharing Economy**

In the previous chapter, we offered a set of design strategies to support physical sharing practices in the context of the sharing economy. Yet it remains unclear how design practitioners can use this type of design research knowledge in their creative practices. The goal of this chapter<sup>1</sup> is *to investigate how designers can specifically support technology-mediated physical sharing practices in the context of the sharing economy* **(G3)**. In order to meet this goal, we first elicited a set of design implications for sharing economy services (see Section 7.1) based on the mapping of the design space between digital and physical sharing described in Chapter 3. Next, using these design implications, we developed a design toolkit and a corresponding methodology for sharing economy services targeted user experience and service designers (see Section 7.2). We then partially validated the toolkit with the view to identifying how it can be adapted to the designers' creative practices in individual and collaborative settings.

At the outset of this chapter, we turn to the key design themes of technologymediated sharing practices introduced in Section 3.3 in order to inform the design of contemporary sharing economy services. In particular, we review the commonalities and differences between digital and physical sharing practices in the light of prior work in HCI. In other words, we reflect on the diversity of shared content, users' motivations to share, audience management, privacy and trust issues, and user experience requirements across both digital and physical sharing practices. This allowed us to formulate an initial set of design implications for devising novel sharing economy services.

<sup>1</sup>Portions of this chapter are also published at NordiCHI'18 [Fedosov, Albano and Langheinrich, 2018] and CHI'19 [Fedosov, Kitazaki, Odom and Langheinrich, 2019].

Based on these design implications, we developed the Sharing Economy Design Cards, a design toolkit for sharing economy services in the form of a card deck, and a corresponding design methodology. The main idea behind the toolkit is to aid the transfer of domain-specific knowledge between design research and practice. We deliberately chose the format of the cards for our toolkit, owing to its familiarity to (and wide adoption among) design practitioners. In order to examine the use of the cards, we subsequently deployed them in two settings: (1) we collected feedback from individual evaluation sessions with a set of designers and sharing economy experts and (2) we conducted two creative workshops with UX and service designers. Our findings showed that the use of the cards not only facilitates the creation of future sharing platforms and services in a collaborative setting, but also helps to improve existing sharing economy services as an individual activity.

## **7.1 Design Implications for Sharing Economy Services**

The goal of this section is to elicit a set of implications for design for sharing economy services, drawing upon the comprehensive mapping of the design space between digital and physical sharing practices described in Chapter 3. Consequently, our point of departure lies within five key themes of technology-mediated sharing practices (see Figure 3.3) introduced in Section 3.3: (1) shared content; (2) audience management; (3) motivations to share; (4) privacy and trust issues; and (5) user experience requirements.

We first briefly review the gist of those themes. **Content** refers to the type of the shared artifact. It addresses the question: "What is being shared?" **Audience** refers to the recipients of the shared content. It addresses questions like "To whom is the content being shared and how is it being communicated?" **Motivations** are what drive people to share. It addresses the question: "Why is the content being shared?" **User Experience** concerns aspects of a user's internal state, the characteristics of the interaction, and the context where interaction between the user and the system occurs. On the whole, it addresses the question "How does sharing take place?" **Privacy and Trust** relates to people's desire to control information dissemination. It addresses questions like: "How do users feel about privacy and trust issues when deciding to share, and how does it affect their choices?"

What is more, our empirical study of technology-mediated sharing practices described in Section 3.3 helped to illustrate the commonalities and differences of sharing of digital and physical artifacts. Five key differences between these two

practices are: (1) the shared content: sharing physical artifacts often encompasses not only the shared material object itself, but also the accompanying layers of (meta)data; in digital sharing, content is exclusively immaterial; (2) the recipients of a shared artifact: unknown audiences in physical sharing vs. family members and friends in digital sharing; (3) the motivations for sharing: physical sharing is often driven by economic and practical needs (e.g., getting monetary benefits), while digital sharing is largely guided by self-expression; (4) the substantial concerns of trust in physical vs digital sharing; and (5) the sharing triggers: in physical sharing, a borrower/renter proactively needs to express an interest in a shared artifact, while sharing digital artifacts is often initiated by a sharer.

Building upon this dichotomy, in what immediately follows, we formulate a set of the implications for design for contemporary and future sharing economy services by reflecting on the key findings from our original study (see Section 3.3) in the light of the related work (see Chapter 2).

#### **7.1.1 Leverage the Twofold Nature of Shared Content**

Many of our participants (e.g., see the quote of Worden on page 36) indicated the dual nature of content when sharing physical artifacts. Besides sharing "a thing" itself (e.g., a car), there is a supporting layer of digital information that is shared along with it. This included both machine-produced forms of information and metadata captured by virtue or use of a platform's digital infrastructure, and human-produced digital records through directly taking and uploading the information (e.g., photos of a car, textual annotations). This information often affords opportunities to build a narrative around the artifact itself. Leveraging nascent research in HCI that aims to bridge the gap between physical artifacts and their digital representations through collecting metadata [Odom et al., 2011], provenance [de Jode et al., 2012] and histories of use [Benford et al., 2016], we see the value for designers to use these strategies to communicate information about the ownership, duration of a share, provide contextual suggestions of use of an artifact, and preserve and share previous interactions with it. This not only can improve the overall user experience with the shared artifact itself, but also can afford opportunities for social interactions around it (for further reflections see Section 6.2.9).

#### **7.1.2 Adjust Levels of Self-Disclosure Over Time**

Our findings (see Section 3.3.3) suggest that physical sharing is largely carried out with unknown people [Ikkala and Lampinen, 2014; Lampinen, 2014; Ozanne

and Ballantine, 2010]. It can be partially explained by the advent of the sharing economy services, where people participate in an exchange for monetary compensation [Bellotti et al., 2015]. To effectively advertise and execute the sharing transaction, sufficient level of details must be provided about the shared artifact or service. Designers of sharing economy platforms should provide appropriate levels of controls for the user that help balance adequate level of disclosure of personal information and the details of a shared artifact. Modern sharing economy platforms incorporate progressive disclosure mechanisms that reveal adequate amounts of content at a given stage in the transaction. In addition to that, service designers may want to consider *concealing information* upon the completion of a transaction, due to some possible negative consequences (as in the case of Danny, who was accused of smoking after having already departed from a rented property, see his quote on page 40). One interesting option in this respect may be smart-contracting technologies [Elsden et al., 2018], which can automatically enforce a "departure contract" by simply retrieving data from installed sensors at home (e.g., smoke detectors). While such technologies may offer straightforward evidence and minimize ambiguities, when it comes to the issues of liability in sharing economy, the extent of their deployment and enforcement should take the larger social organization of the service into consideration, since it can influence social relationships among peers and the community at large. Finally, in contrast to digital sharing, where shared content can scale to reach multiple audiences at the same time [Vitak, 2012], physical sharing limits people share to one individual (or small group) at a time, which may delay decision-making as in the case of Dacie (see her quote on page 39). We suggest that designers of future physical sharing services explore viable user interface techniques (e.g., access control mechanisms), where the shared artifact (and their digital counterparts) can be ultimately accessed and maintained by a group of involved stakeholders.

#### **7.1.3 Attend to Communicative Aspects of Physical Sharing**

When it comes to motivations to share, we want to return to our framing of two different logics of sharing (Figure 3.2). We found that prior research in HCI has paid a lot of attention to digital sharing as an act of *communication*, while only few works explored this logic in the context of physical sharing practices (e.g., sharing printed photos [Frohlich et al., 2002; Miller and Edwards, 2007; Nunes et al., 2008]). Researchers explained that participation in online sharing stems from people's desires to create and maintain social ties [Goh et al., 2009; Lange, 2007], needs for self-expression (e.g., [Goh et al., 2009; Van House et al., 2005]), and generally from the hedonic qualities of sharing experiences online (e.g., [Acquisti

and Gross, 2006; Bayer et al., 2016]). However, these social phenomena were less accentuated in prior research into physical sharing. This may indicate an opportunity for research to explore communicative aspects of physical sharing. In practice, designers of sharing economy services can explicitly emphasize the advantages of maintaining social relationships, for example, through illustrating the benefits of reciprocity. As our participant Morten proposed (see his quote on page 44), this can facilitate enrolling new users in a sharing economy platform.

#### **7.1.4 Provide Instruments to Improve Trust**

Our findings (see Section 3.3.3) identified that the main concerns of sharing physical artifacts are rooted in the lack of trust in a counterpart of the sharing transaction [Ikkala and Lampinen, 2014; Luckner et al., 2015]. Given that sharing economy services are carried out broadly with unknown individuals, trust is something that strangers do not naturally have for each other. Therefore, we have emphasized that it is of utmost importance for designers of physical sharing services to provide mechanisms and tools to build trust between potential exchange partners. Furthermore, we speculate that presenting accounts of successful exchanges may contribute to the overall endurance and growth of the sharing platforms and communities over time. Some commercial sharing economy services have already adapted various mechanisms to build trust within the community and the platform through reputation review systems, transparent profiling, and offline-identification for the providers of the shared resources. It follows that in order to build attractive and trustworthy social profiles within platforms, designers need to explain the benefits and provide tools to de-anonymize participants within a sharing platform, as aliases, nicknames, or incomplete profiles are not considered trustworthy to engage in community building [Bardhi and Eckhardt, 2012]. Note that while more disclosures are encouraged, owing to the fact that self-descriptive profiles can contribute to making informed decisions [Ert et al., 2016] and are perceived more trustworthy [Ma et al., 2017], there may be some negative consequences designers should be aware of, such as "digital" discrimination based on the aspects of appearance, e.g., race, gender [Edelman and Luca, 2014].

#### **7.1.5 Explore Sharing Triggers**

Throughout our analysis (see Section 3.3.3), we have encountered a difference between the triggers to share in physical and digital sharing. When sharing physical artifacts, the number of shares that happen by request from the audience

is much more represented than whilst sharing digital artifacts [Bellotti et al., 2014; Lampinen et al., 2013; Ozanne and Ballantine, 2010]. The difference may be explained by the motivations to share. While digital sharing is driven by self-expression and self-representation, physical sharing motivations are largely instrumental and driven by inquires to borrow an object or provide a service based on the demand of the audience. Designers of future physical sharing platforms may proactively explore the needs of the audience to leverage these behaviors.

Note that the pro-social rhetoric of sharing (e.g., openness, trust, commonality and understanding between people) [John, 2017] is rarely placed at the center of attention in popular profit-driven sharing economy services. Nevertheless, we envision that the wider adoption of platform cooperatives [Scholz, 2016], with their commitments to cultural and community values over economic gain, can empower service designers to develop and evaluate sharing triggers that follow from social interactions.

Ultimately, in our data (see Section 3.3.3), we found no instances of sharing 'determined by the system' in physical sharing. However, examples of such practices exist (e.g. Airbnb's 'instant booking' feature, which allows guests who meet predefined requirements to automatically book a space without an additional host's approval). Sharing economy services could take a step further in this direction and allow a supporting digital platform, for example, to instantly share a WiFi password, provide an access code for a building, or even open a door or locker using some IoT-based technology (e.g., Slock.it) after a user confirms a reservation. Designers of physical sharing services could explore the opportunities to include automatic sharing capabilities, based on user needs and available infrastructure. For example, community-owned lending libraries of things (e.g., thethingery.com) may benefit from the computerized pick-up/drop-off stations (similarly to the self-service parcel lockers used by a number of European postal services) for their members to facilitate exchanges of tools and equipment, and to assist in emergency preparedness in neighborhoods.

#### **7.1.6 Towards Operationalizing the Design Implications**

In Section 3.3, based on an extensive literature review and expert interviews, we offered a mapping of the design space between digital and physical sharing. In particular, we presented 13 sharing dimensions (see Figure 3.3) that characterize technology-mediated sharing practices. We aggregated them into five main themes: (1) the diversity of shared content; (2) audience management; (3) motivations to share; (4) privacy and trust issues; and (5) user experience requirements. Using these dimensions, we described commonalities and differences

between sharing digital and physical artifacts across eight broad sharing practices (see Section 3.3.3). Finally, in this section, we reflected on this dichotomy and elicited a set of design implications for devising future sharing economy services.

As the next step, drawing on our empirically-extracted design implications, we present a design toolkit for sharing economy services. The toolkit covers the five aforementioned key design themes and for each, offers a set of actionable recommendations for designers to devise value-added services for the sharing economy. The toolkit also supplies each recommendation with an example of a user interface from an existing sharing platform or service that implements a given recommendation. In the next section, we describe our toolkit and present the insights from its two field deployments with design practitioners.

## **7.2 The Design Toolkit for Sharing Economy Services**

Prior work in the HCI literature highlighted a key need to support designers in the sharing economy [Light and Miskelly, 2015], owing to the rapid proliferation of both profit-driven and non-profit forms of the sharing economy and the growing body of research knowledge in the area [Dillahunt et al., 2017]. However, design practitioners do not often adopt this type of research knowledge since they find it too abstract, too difficult to use, and too hard to locate [Norman, 2010; Roedl and Stolterman, 2013]. Driven by the goal to understand how designers of online sharing platforms and services could both improve existing sharing economy platforms and create new ones, we have sought inspiration in *translational resources* [Colusso et al., 2017] such as design toolkits, which have shown promise in effectively transferring knowledge between design research and practice [Deng et al., 2014].

We developed a 24-cards deck called the Sharing Economy Design Cards (SEDC), which provides domain-specific insights for designers on the diversity of shared content, users' motivations to share, audience management, privacy and trust issues, and user experience requirements – all in the context of the sharing economy. We initially deployed the cards with 16 design practitioners and sharing economy domain experts to gather their individual feedback on the content, possible applications, and usefulness of the cards for evaluating existing sharing economy services. We also deployed the cards in two design workshops with 5 participants each to explore their use in a collaborative setting. Our work addresses the following research questions:

We offer two main contributions. Firstly, we provide insights gathered in the context of two deployment settings of the cards (individual and group) and discuss how they help advance both design research and practice in the context of the sharing economy. Secondly, we present the SEDC themselves and the corresponding design methodology.

#### **7.2.1 Background**

Our work lies at the intersection of two principle research areas: (1) the sociotechnical challenges of the sharing economy and (2) the design cards as a genre of design toolkits.

In Section 2.4, we reviewed the body of work that looked at the attendant challenges of different forms of the sharing economy. Of particular relevance to this study is a set of design strategies for better sustaining physical sharing practices in local communities and collectives [Light and Miskelly, 2015]. In light of this prior research, our work facilitates the transfer of knowledge from design research to design practice through cards – a familiar toolkit among practitioners – and explores their use within established design methods such as thinking aloud critique [Nielsen, 1994] and collaborative workshops [Halskov and Dalsgård, 2006].

Design cards have been created and evaluated in various contexts. To name a few, cards have been suggested to facilitate the conceptualization of Internetof-Things applications [Mora et al., 2017], to raise awareness of emergent data protection regulations [Luger et al., 2015], to support the design of information systems for international justice [Logler et al., 2018] and to design interactive artifacts for ageing populations [Nicenboim et al., 2018]. Others targeted more abstract human qualities such as values [Friedman and Hendry, 2012], resourcefulness [Nicenboim et al., 2018], playfulness [Lucero and Arrasvuori, 2010], and creativity [Lucero et al., 2016] as part of the design process. We aim to extend these ideas in the context of the sharing economy.

Prior research showed that cards can support various design activities: understanding a phenomenon at hand [Colusso et al., 2018], collaborative [Friedman and Hendry, 2012] and playful ideation [Lucero and Arrasvuori, 2010], co-design (e.g., [Lucero et al., 2016]), formative evaluation of design concepts [Deng et al., 2014], and advocacy [Colusso et al., 2017]. In our work, we are interested in

understanding whether design cards can be also used in individual summative evaluation activities akin to heuristic evaluations to surface design issues with existing sharing economy platforms.

Prior work also outlined techniques aimed at better supporting designers and researchers to create their own design cards [Halskov and Dalsgård, 2006] and supporting materials such as design worksheets [Logler et al., 2018] and canvases [Mora et al., 2017] to guide cards' use. Drawing on these efforts, we developed a corresponding design methodology to facilitate design cards use in a collaborative setting.

In summary, prior research suggested various techniques and methods to apply design cards to support the creation of interactive systems within different application domains. Our work builds upon this prior research to explore how our SEDC can be leveraged in different stages of the design process, and in various settings (e.g., group and individual design activities), all in the context of the sharing economy.

#### **7.2.2 Sharing Economy Design Cards**

Drawing on the recent survey of the sharing economy in the computing literature [Dillahunt et al., 2017], and our own comparative review of technologymediated sharing practices (see Section 3.3.3), we elicited a set of design recommendations to support designers with domain-specific knowledge. Given the difficulty of having this type of design research knowledge adapted by practitioners [Roedl and Stolterman, 2013], our goal was to aid designers in operationalizing the research knowledge in the context of sharing economy. The recent work of Colusso et al. [2017] calls for more practitioner-oriented translational resources, which could be used to engage designers to adapt the knowledge produced by design researchers in their practices. Following their work, we developed the SEDC and tailored them for service and UX design practitioners by providing actionable recommendations, genuine examples, and simplified search through keywords. We specifically chose the focus our research inquiry on design cards since this genre of design toolkits can provide an adequate level of details to inform the design (e.g., UI), and proved useful in combination to familiar design methodologies (e.g., the design sprint) [Colusso et al., 2018].

Figure 7.1 shows the face of one card (out of 24) in a SEDC deck as an example (plus 4 partially hidden cards). The full set is included in Annex B.

In terms of visual representation and layout, our cards were in part inspired by the Tiles IoT Toolkit [Mora et al., 2017] and the IDEO Method Cards (https://www.ideo.com/post/method-cards). Specifically, from the Tiles IoT

*Figure 7.1.* The SEDC examples for each theme: (a) Content; (b) Audience; (c) UX; (d) Privacy and Trust; (e) Motivations

Toolkit we took inspiration in distinctly-colored decks to ensure the ease of referencing, browsing and sorting cards, while from the IDEO Method Cards we were encouraged to add succinct descriptions to further inform and inspire designers. We adapted the structure of the cards from a mockup suggested by Colusso et al. [2017], which is grounded in their empirical research on design toolkits and based on multiple iterations with UX designers. Drawing on their most recent work on behavioral change cards [Colusso et al., 2018], we decided to include existing design examples in the form of screenshots of user interfaces, which were found extremely useful by their participants.

We have divided the front side of each card into seven "sections" (see Figure 7.1c), namely (1) a card's theme, (2) a leading question, (3) a design goal; (4) searchable keywords; (5) an actionable recommendation; (6) a detailed description; and (7) an example from an existing service. We have used bold and light typefaces to create a visual structure to the cards and to aid their readability. The **goal** and the **recommendation** are placed next to each other to quickly understand their relation among each other (following the Gestalt Law of Proximity). The **examples** have been chosen from existing sharing economy platforms and have been placed on the right side of the **recommendation**, offering its interpretation on the user interface level. We envision the cards to be printed in a minimum format of 10.6 by 2.8 inches with rounded corners to ensure comfortable use around a collaborative working area (e.g., a desk, a board). The back of each card has a recurrent pattern featuring the name of the theme on the correspondingly colored background.

The SEDC deck aims to explore design opportunities characterizing different angles of a sharing economy platform or service. The cards' themes were drawn

from a systematic literature review of technology-mediated sharing practices of both physical and digital artifacts (see Section 3.3). The deck details five themes (each represented with a colored suit, see Figure 7.1), which allow a designer to identify and describe specific characteristics of a service/tool at hand: **Content** (Blue), **Audience** (Orange), **Motivations** (Green), **Privacy and Trust** (Red), and **User Experience** (Purple). Themes set the foundation to answer a set of core sharing questions (see "Leading question" label on Figure 7.1).  and "How is the sharing takes place?"

Note that the themes and the recommendations are neither exhaustive nor expected to be the orthogonal to each other. They are developed based on a qualitative account of 87 papers that studied technology-mediated sharing practices (see Section 7.1). However, to minimize this limitation, we have deployed the SEDC with a total of 26 participants to seek their feedback on the cards' content and to evaluate their use within designers' creative processes. Additionally, for each theme we have added a blank card, such that participants could formulate their own recommendation and suggest an example based on their own expertise.

#### **7.2.3 Field Deployments**

In order to understand the opportunities and difficulties using the SEDC in the designers' creative practices (RQ1), and to detail their use in different phases of the design process (RQ2), we conducted two user studies. We hypothesized that the SEDC can be used not only during early stages of the design, such as initial ideation or concept development (as suggested by the prior art), but also support the evaluation of existing platforms and tools with the goal to find usability issues and to improve overall user experience. What is more, we envisioned cards to be used during individual activities akin to heuristic critique or expert interviews, as well as in group design activities drawing on participatory [Bødker et al., 1995] and co-design [Sanders and Stappers, 2008] methodology. That is why we first conducted a study with individual participants, and then organized two collaborative workshops in a group setting. During both deployment settings, participants provided us their feedback on the cards, as well as reflected on their use. While our initial deployments did not explicitly engage with participants at their place of work [Roedl and Stolterman, 2013], we nonetheless see the value of adopting this approach to map this emergent design space. Wider dissemination of the cards marks a salient opportunity to further explore the extensibility of their value for professional design practice [Goodman et al., 2011].

#### **Study 1: Individual Interviews**

At the outset we individually engaged with 5 sharing economy domain experts and 11 design practitioners (16 people in total, 11 were female, all used sharing economy services actively) in semi-structured interviews. The average age of participants was 31.3 years old (*SD* = 3.6), they held various occupations including UX designer, graphic designer, interaction designer, start-up founder, academics (with backgrounds in statistics, sociology and economics) who conduct research in the sharing economy area. The participants' average job experience at the current position was 6.1 years (*SD* = 4.6). Most of our participants live in Western and Central Europe, five of them were from Argentina, one from China and one from the US. We particularly wanted to focus on non-US context since researchers suggested that those populations were less explored in the area of sharing economy [Dillahunt et al., 2017]. The goal of this deployment was twofold: (1) to elicit participants' professional reflections about the SEDC themselves and (2) to understand whether and how the cards can be used for evaluating an existing sharing economy platform that is most familiar to them.

The participants were initially recruited through our extensive professional networks; we then employed a snowball sampling strategy to reach out to more participants. We sent a PDF document featuring the SEDC deck and an introductory note (outlining the purpose of the interview) to participants a few days before the scheduled interview in order for them to get familiar with the cards. During the interview, we asked each participant to interpret at least two "specific" cards (we always picked different cards to ensure the coverage of the whole deck). We then inquired about one sharing economy service that participants have had the most experience with. Later, we engaged participants in a think aloud session [Nielsen, 1994]: using their offered interpretation, we asked them to reflect upon the sharing economy service they have selected. We challenged designers to discuss the content of a UX report with the goal to identify shortcomings and opportunity areas of this sharing economy service. For example, we asked them "How do you think the cards informed your conclusions?" For the five sharing economy experts we asked more detailed feedback on the content and the structure of the cards. For instance, we inquired "What aspect of the card (see Figure 7.1c) have you found most useful when thinking about this service?" and "What does that card (see Figure 7.1d) prompt you to do?" to elicit a critical reflection on a service at hand.

Each interview session lasted approximately 60 minutes, was audio recorded and transcribed verbatim. We conducted interviews either in person or over Skype and took extensive field notes; findings after each interview were captured

immediately in reflective field memos [Glaser and Strauss, 2009], which we reviewed throughout our analysis.

#### **Study 2: Collaborative Workshops**

In order to better understand the usage of the cards in group settings, we have organized two practitioner-oriented workshops, drawing upon collaborative design events such as the Inspiration Card Workshop [Halskov and Dalsgård, 2006] and design sprints [Knapp et al., 2016; Colusso et al., 2018]. Study participants were recruited by distributing a study invitation within various online communities, including user experience and front-end development meetup groups, local designers' Slack channels, email distribution lists, and through authors' social media accounts.

In total, 10 participants participated in our study. We conducted two 2-hour workshops with 5 participants each (see Figure 7.2). We tried to evenly distribute them based upon their background and work experience. Similar to Study 1, we recruited participants from both design and sharing economy communities. The average age of participants was 33.1 years (*SD* = 8.4), 6 of them were female. They all live in a Western European country and have worked at their current position for on average 6.0 years (*SD* = 4.9).

The goal of the workshops was to assess the potential value of the SEDC in the process of creating value-added sharing economy services. More specifically, we aimed to understand how and whether participants would find the card deck helpful when devising new sharing economy services. We adapted the Google

*Figure 7.2.* The Sharing Economy Design Sprint

design sprint format – that is mapping, sketching, deciding, and prototyping activities [Knapp et al., 2016] – since it is one of the most widely used approaches in professional practice and was familiar to our participants.

**Sharing Economy Design Sprint** In contrast to Study 1, participants were not able to spend much time reflecting on the SEDC. We specifically chose the sprint format as being close to industry demands, where designers have to make decisions within a limited time and with limited resources [Roedl and Stolterman, 2013]. We took inspiration from the Behavior Change Design Sprint process [Colusso et al., 2018], while modifying several activities that its authors found problematic. Figure 7.3a presents the input resources for the design sprint, namely: a design brief, the models of personas and a scenario. In addition to employing the SEDC, we developed three supporting templates: (1) a map canvas, (2) an idea template and (3) the prototype templates, which we have used during the sprint (see Figure 7.3b). All of these resources are included in Annex B.

*Figure 7.3.* The Sharing Economy Design Sprint: (a) input materials; (b) worksheets

The Sharing Economy Design Sprint lasted for 120 minutes and contained eight individual and group activities (see Table 7.1). We video-recorded all sessions (see Figure 7.2) and then transcribed the parts that were relevant to our research questions. In addition to that, we took the field notes during the workshop and photographed the materials that participants produced during the sprint (see Figure 7.4d).

*Table 7.1.* Activities of the Sharing Economy Design Sprint

#### **Data Analysis**

Our data analysis draws upon various sources from our fieldwork: participant observations from two workshops, analysis of the video data, participants' reports produced during the workshops, and semi-structured interviews. We used affinity diagramming [Beyer and Holtzblatt, 1997] to understand the collected data thematically and to model similarities and differences across participants. We followed an iterative process, going back and forth between the data, the researchers' notes, and the emerging structure of empirical categories, which we developed through recurrent reading of the material [Glaser and Strauss, 2009]. We also held meetings with researchers outside of the project to challenge our assumptions and to corroborate the themes. We distilled four sets of results that reveal at which stage of the design process, and how, the SEDC can be used in both individual and group activities. In the following section, we present examples that help capture these themes and support them with participants' quotes from both our studies. We use pseudonyms to describe study participants.

#### **7.2.4 Findings**

We elicited a range of reflections and reactions on the SEDC and their use from designers and sharing economy domain experts – from perceptions of the cards' usefulness, to considerations on the use of the cards in their own work, to prospective adaptation of the cards in different stages of service development process, to recommendations on how to improve the cards further.

#### **Perceptions of the Cards**

Our participants reflected on the structure of the cards and commented on each individual section with respect to its usefulness for their creative processes. Blanca, 30, while browsing a card, outlined the value of the **Recommendation** section for the designers:

*"Recommendations are more specific than Goals, I found them more useful. What's in the Recommendation is a [set of] sub-goals that are often what a designer must deal with, it is more relevant for a designer. Connecting recommendations to big goals, as you have done, makes sense to me."*

This comment illustrates that the **Recommendation** worked as an instrument to achieve the **Goal**. Furthermore, Aubry and Emma noticed its reflective qualities. Emma, 31, further suggested to formulate it in the form of the question to trigger this process: *"because something poses a question on the card makes you think"*. Our participants felt that one of the most informative parts of a card was its **Description**.

*"[This] statement (see Description on Figure 7.1c) suggests a study behind it. It feels trustworthy, it helps to convey the Goal "Reduce complexity". It felt bulletproof, it made me believe that this goal is useful, and that I should stick to it because there are studies showing that it works."* (Pierre)

This quote illustrates the value of statistical and other empirical information in the designer's activity when it comes to advocating their designs to a group of stakeholders. One of the most discussed section of the card was the **Example**. It not only served the purpose of stimulating alternative designs, but was also regarded as eye-catching, inspirational, and clarifying the content of the card at large. Rebecca, 26, reaffirmed the latter:

*"Examples clarify a lot what the card is trying to say, they are really useful, especially because the example are things that people can understand – at least I understand what they refer to [... ] They are good practices of products that achieve the goal."*

This quote refers to a practical example taken from a famous sharing economy service, which allowed the designers to relate the problem to their own work. It provided them both "legitimacy" and intuition that this UI pattern works in practice, hence could be considered reliable and trustworthy.

Danny, 31, proposed to use the **Keywords** section to allow searching for design patterns:

*"I can see that search is a big problem for designers, they do not know where to look for those cards."*

In a handful of cases, the **Keywords** also acted as a signifier summarizing the whole content of the cards, especially in the collaborative activities during the sprint, when lots of workshop materials were on the table at the same time (see Figure 7.2).

The majority of our participants agreed that the **Motivation**, **Content**, and **Audience** themes of the cards were rather important at the initial stages of the development of new design concepts, while **User Experience** and **Privacy & Trust** would come at the later stages of the development. Conversely, Adam, 30, mentioned that some of the themes, such as **Privacy & Trust**, were often overlooked in the early stages of the design of a new service:

*"Privacy is often left [out] in the design stage, usually the solution [architect] tries to add this at a later stage and designers don't think about it. [The card] (see Figure 7.1d) just reminds them that they have to bring this issue [up], which is very good."*

What is more, participants related the non-hierarchical structure of the themes with fluid boundaries among them:

*"Maybe because I am an interaction designer, [when] thinking about UX, we extend it to all the other topics. Privacy & Trust, and Motivation are parts of my experience. It [may] not [be] the same for people with different background."* (Toby, 31).

This instance illustrates that the **UX** theme can be perceived as a broader umbrella that incorporate other dimensions. Gladys, 30, developed this idea:

*"Some cards like [No.] 6 (see Figure 7.1a) and [No.] 21 share the same Goal "Provide pleasurable interactions", I think they can be combined and connected in different ways since there are some overlaps exists in them. One strategy, I think, is to make designers explore those connections and references while they are playing [the cards]"*

As a matter of fact, we observed that some of our workshop participants used several cards at once to sketch-out their ideas in order to meet the suggested "call to action". Refer to Figure 7.2, where two participants on the right have

several cards spread out around them during the prototyping exercise. Most of the participants agreed that the **Motivation** theme can be seen as a nucleus of any service design.

*"The motivation in my opinion is most important to understand what you are really doing. I like a lot the emphasis on the desirable values, quality and convenience of the service. It is the core [... ] it is what you are selling. If you don't have great value and a great way to engage [people] and [to] create social relationship based on reciprocity [. . . ] these kinds of things are really crucial when it comes to a sharing economy platform [. . . ] like authenticity in [the] case of Airbnb."* (Aubry, 30).

Notably in this instance, Aubry adapted the same vocabulary that we used in the cards, which suggests the informative and educational value of the card deck at large.

Collectively, these reflections illustrate how our participants attributed importance to the different sections of the SEDC, and how these provoked discussions on the fuzzy boundaries between the cards' thematic areas. Next, we provide further details about the challenges and opportunities participants raised within our two studies.

#### **The Opportunities and Difficulties of Adapting Cards**

Participants reflected upon the opportunities and difficulties of adapting our cards in their own creative processes, and saw a potential to use the design cards beyond the sharing economy. Participants discussed the value of the cards to support both existing and new instances of sharing economy services, and argued on the importance of looking beyond profit-driven aspirations.

"*Sharing economy platforms are a rather new [phenomena]. There are many of them now – you pay and then get a service. The cards let a designer step back and look at the bigger picture, to slow down a bit and to think how we can improve [a service] in different ways beyond [an] economic [point of view]."* (Gladys, 30).

This quote illustrates the potential of the cards to mobilize the values of collaboration and participation – the cornerstones of platform cooperativism. Pierre, 37, argued that the content of the card could partially replace a human expert when it comes to acquiring the domain knowledge:

*"I can imagine it is like a suggestion from an expert, instead of sitting and booking someone's time, I can use the cards and try to help myself as a designer without professional [domain expertise]."*

With reference to the challenges in adapting cards in the sprint format, Sarah, 42, explained that more time is required to process the **recommendations** given in the cards, which can be difficult in a high-paced design process:

*"You have to be there, read a lot. It takes some time to understand. The [card's] Goal and [the] Example were more direct"* (see Figure 7.1c).

Another challenge that emerged from the data is related to the cards' **examples**.

*"Those examples make me focus and comply to the goal in a way that may limit my imagination. . . [however] it may be good for those who struggle to interpret a goal."* (Pierre, 37).

This instance illustrates that even though the **examples** were regarded as very informative and clarifying, they also raised concerns of being too specific. Nevertheless, participants found them to be especially beneficial for less experienced designers or even non-designers. Similarly, the **Keywords** section of the cards helped non-designers to make sense of the cards, like in the case of Josepha, 35:

*"The goal is a bit vague to me, the keywords helps you to clarify the goal. Without the keywords I would not know [how to interpret] the goal 'Reduce complexity' (see Figure 7.1c)."*

Several study participants suggested applications for the SEDC beyond the context of sharing economy. Given the broadly formulated cards' design goals and the themes, participants suggested their use in various areas, for instance product strategy, educational technology, e-commerce, games development, designing online platforms for fitness tracking and creating social media apps. Blanca, 30, explained:

*"[Cards] provide some ideas for design goals that I should pay attention, [it] can be useful to incorporate those into interviews within my own field of work with users. [The] Goals are quite broad such as "Create value" for the sure, "Reduce complexity" (see e.g., Figure 7.1c). They are [also hold] true in my domain, that is e-commerce, as well when it comes to the user [research]."*

Worden, 32 also saw the value of cards in his teaching and research activities:

*"Cards stimulate thinking of the practices and platforms in a systematic way, also it could be a good brainstorming tool even for researcher to coming up with new research ideas and projects."*

Collectively, these reflections help to anticipate designers' opportunities and challenges when using the cards in their creative processes. Furthermore, the SEDC provoked reflective thinking on possible applications of the cards in design of online platforms and services, where people share their personal digital information (e.g., captured from the wearable devices).

#### **Serving Different Stages of a Design Process**

From the participants observations and the video analysis, we have quickly discovered that our participants have used cards on the different stages of the sprint, as well during individual interviews. Morten, 33, outlined:

*"First of all, it gives a quite nice overview on the different themes/factors that affect design of a service [as represented by] higher-level themes Content, Audience, Motivations etc as a bigger building blocks of the whole UX of the service. Also, by picking any of these cards up, you can use [it as] a checking point whether the particular recommendation is taken into account in the [current] design or even generating idea[s] for new features that the service does not yet have. I see value in both evaluation and designing new features."*

From our field data, we have elicited five main stages of the design process where the SEDC have been used including, namely: (1) focused brainstorming, (2) prototyping, (3) communicating, (4) refining, and (5) evaluating.

**1. Focused Brainstorming** The cards helped participants to initiate and engage in focused brainstorming sessions during the sprint. Participants were prompted by the cards' **Goal**, **Keywords** and **Recommendation** to start developing and discussing their ideas. Participants used not only individual cards to reflect upon their content, but also the combinations of cards looking for similar threads. Aubry, 30, explained:

*"[I was] going deeper and deeper within a single goal per [theme] and expanded it to the extreme in order to see how this goal could be implemented on the Content, Audience, Privacy & Trust etc. That drives the design in all these different aspects. One can focus on one specific goal and that could be seen or interpreted [through] different layers [of] Content, Motivations, UX in order to build a coherent story."*

What is more, the SEDC guided participants brainstorming process by revealing the underlying domain-specific issues that designers may not be aware of.

*"I think the cards could be used at the start of developing/designing a platform. They are easy to use and following them at early stages perhaps could contribute quicker to the [overall project] success. People behind the platform should be informed about those issues [the] cards bring up."* (Dacie, 35).

This instance demonstrates the value of the cards in revealing the prospective challenges that designers may want to anticipate in the context of sharing economy.

**2. Prototyping and Sketching** As expected, the cards were widely used during sketching and prototyping activities. In particular, the cards' **Goal** and **Recommendation** part was useful to quickly outline some ideas on the post-it notes during the sprint, while the **Example** parts were heavily used during creating low-fidelity prototypes to flesh out some ideas from the existing platforms and services. Toby, 31, explained:

*"I think in the prototyping phase, they were particularly useful. I think the Example [part] was one of that gave us more insights, more inspirations to draw something"*

Figure 7.2 on page 185 shows the participants during the prototyping phase; some participant worked in pairs, while others reviewed the cards individually to develop their designs.

**3. Communicating** Both interview participants, as well as the workshop participants, found beneficial to use the cards to advocate their designs to their colleagues or to a group of stakeholders. Emma, 31, detailed how the **Description** part of the card was crucial during this phase:

*"I also like images and a little stats that you have here in the card (see Description on Figure 7.1c). That is the one of the first things that we mentioned because if you are going to present to your client, which is a new startup, [in] this deliverable, you can use these cards as a kind of give yourself some credibility, advocating particular design [decisions]."*

**4. Refining** Figure 7.4a shows how participants used the cards to refine and evaluate their own design concepts. In this particular figure, Diana, 35, explained:

*"The features I added here thanks to the cards were the donate [option], age selection and storytelling."*

What is more, participants reported that cards helped them to understand some design issues that they had not earlier anticipated. Jehanna, 31, explained:

*"The card (see Figure 7.1d) helped me to notice a problem I didn't take into consideration [. . . ]. Even though I didn't find a solution to the issue just now, the card helped me to approach the problem."*

**5. Evaluating** The majority of our participants agreed that the cards can be used as a guiding tool to evaluate the existing platforms and services. Like in the case of Delora, 32:

*"I see these card deck as a guidebook. For me as an owner of the [sharing economy] service facing some issues with community-building cards provide some ideas to identify particular issues with my audiences. I found for instance, in [the card No.] 12 (see Figure 7.1e), [the] goal 'Reach out and engage your audience' helpful and [the card] provides a clear recommendation how to [attend] it."*

This instance illustrates that the SEDC can perceived as a checklist featuring best practices, which can be cross-checked against platforms' designs. Morten, 33, provided further detail:

*"For example, picking out one of these cards and checking that the goal is already designed/implemented in the service or there will be more work to do. Also after that moving to the right side of the card (see Example on Figure 7.1c) and checking some concrete examples how to manifest these kind of goals to the UI level."*

The SEDC facilitated our participants to identify existing design flaws, Julie, 27, mentioned:

*"I believe Airbnb are doing quite the opposite to what the card recommends, here [this card] (see Figure 7.1c) suggests to identify the needs of the users and to trigger things to improve the service with them, but I don't receive good recommendations of things I'm interested in. I just opened the app and I don't see any of the places I searched before, they [Airbnb] show me these fancy houses I'm not going to rent because they are too expensive."*

Furthermore, the cards offered potential design solutions for those problems:

*"For an average user, it is hard to say often whether [rating] 4.2 is good or bad. Airbnb could provide some contextual information, such as average ratings in certain city, explain what this rating mean. Like if you click on "Accuracy", it can be described for those who opt-in to learn more about it."* (Worden, 32).

In addition to that, the SEDC provided necessary resources to our participants to develop the protocols for future user studies as in the case of Blanca, 30:

*"If you want to understand how people perceive a platform it makes total sense to me [using the cards], it gives me good examples of what to ask and what you should not miss [... ] if you need to focus on the Content, you need all the Examples and all the Recommendations of those [. . . ] it helps you to go straight to the point."*

Finally, several participants contemplated that the cards can be used to structure their design feedback and critique.

*"I do not have to think about the process. The card is a hint for me to use within my expert feedback. The colored [themes] are helping me to structure my thoughts and the overall documentation from different perspectives. There are some ready-made suggestions that I can communicate to a client. It provides me a certain confidence, even [when it comes] to naming sections of the report."* (Pierre, 37).

Collectively, these reflections confirm that the cards could be used in the different stages of the design process from assisting in initial ideation sessions to facilitating the reporting to the stakeholders. In what immediately follows, we detail how the SEDC played out in different stages of the service/platform design.

#### **Developing Design Material Using the Cards**

From the collected data, we have observed that the SEDC can generate various design materials to create or improve a service. Our Study 1 participants used the cards to inform the structure and the content of a UX report including user flows, customer journey maps, and propose adjustments to the UI. Pierre, 37, detailed this while evaluating an existing platform:

*"I have built up a state-map of functions to decompose the UI into the basic functions of different components and I am trying to find inconsistencies between certain [application] logics, which failed [within a service], and [to spot any] misleading components."*

Furthermore, Bobby, 33, elaborated that he used the cards to uncover platform shortcomings and to support their reporting:

*"I guess a good way to show it would be [... ] to take the card (see Figure 7.1c) and replace the example with the exact block from [our own service]. If I can do that, then we have to be doing things right, but if the example doesn't fit, that means we're failing in this aspect."*

During Study 2, participants used the cards to develop concrete service designs. For example, Figure 7.4d shows the filled idea template (and corresponding prototyping templates), which describes a design concept of a local toy bank and its target audiences, namely parents and orphanages. Specifically, the participants proposed an online service that would support the renting and sharing of

*Figure 7.4.* Design materials produced at the sprint: (a) value-added features based on the cards highlighted in yellow with red arrows; (b) user flows, examples of content, target audiences, and UX goals; (c) wireframes and their relation to the cards; (d) an example of a final concept

upcycled toys. The cards not only facilitated the generation of various concepts, but also served to develop and to refine the ideas on the user interface level (see highlighted content on Figure 7.4a). The cards also helped participants mindfully attend to the design goal by incorporating new functionalities, such as storytelling, or attending to the emotional aspects of belonging and intimacy. In particular, Figure 7.4c illustrates how Amy placed the explanatory notes next to her prototypes, summarizing the role of a particular card in her design decisions. In this instance, Amy demonstrated her interpretation (on the UI level) of the card's **Goal** "Build a common space" (see Figure 7.1b) for platform's users by affording them to create personal stories and to link them to the shared toys. Sarah illustrated (see Figure 7.4b) how the cards helped her to not only establish the UX goals of the service (e.g., enhance sociability), but also assisted her in the process of wireframing, establishing an interactive flow, and the creation of examples of the shared artifacts and the target audiences for it, stemming from the **Content** and **Audience** themes of the cards.

Collectively, these reflections help to demonstrate how the cards were instrumental in different parts of a design process: from detailing nuances at the present design idea, to fostering interactive scenarios, to helping to identify and report design flaws in existing sharing economy services.

#### **7.2.5 Supporting the Design Processes**

Our findings show that the SEDC enabled speculation on the role of the UX in the service development, provided hands-on guidance on different parts of the design process, facilitated creating new design material to inform the decision-making, and enabled speculation on future-looking opportunities of cards' use beyond devising sharing economy services. In what immediately follows, we discuss how the SEDC help advance the design practice and design research in the context of sharing economy.

Despite our work focusing on studying designers in design workshops outside of their usual place of practice, we have ensured that the exercises we have performed with designers are situated around their core activities at work, that is collaboration and communication [Roedl and Stolterman, 2013]. Those activities were implicitly included in the stages of the design sprint, namely Deciding and Advocating phases (see Table 7.1). In the Deciding phase, participants have to synthesize their design ideas, establish a group consensus, and eventually pick 1–2 design alternatives, while in the Advocating phase the participants were required to advocate their designs to the set of (imagined) stakeholders. While numerous prior studies of design cards (e.g., [Lucero and Arrasvuori, 2010; Mora

et al., 2017]) have actively supported the divergence steps of the design process, our research highlights key value in better enabling convergence activities.

Following recent work of Colusso et al. [2018], we have adapted the design sprint process in our Study 2 in the context of the sharing economy. While, several of our participants felt that more time is required to reflect upon cards' **recommendations**, we specifically chose this high-paced approach to account for the ongoing issues of limited time and resources during the design process, which practitioners face in the real-life product development projects [Roedl and Stolterman, 2013]. To address this concern, we believe that exposing the cards to participants prior to any design activity can be beneficial. Therefore, in order to ensure we would receive adequate feedback on the cards' content, we have accommodated an individual activity with designers and sharing economy experts in Study 1. In contrast to prior work [Colusso et al., 2018], where participants were struggled to reflect on theoretical frames brought by the design cards, this time-unbound activity allowed us to elicit deeper reflections on the sharing economy concepts.

Our findings revealed that some of the design ideas that emerged during the sprint were attributed to the continuous interaction among participants (see Figure 7.2). Yet, similarly to [Colusso et al., 2018], our participants were able to further advance and expand their designs using the cards' **examples** and **recommendations** (see Figure 7.4a).

Finally, individual uses of design toolkits, such as cards, are rarely described in the design research literature, perhaps due to the collaborative nature of the design process at large. Friedman and Hendry [2012] suggested that card-based design toolkits can be used as "an analytic technique tool", which our research supports and helps extend through an empirical case. Our SEDC were used not only in supporting groupwork to create new design concepts of sharing economy services, but also in the individual activity akin to expert critique to identify design issues of the existing sharing economy platforms.

#### **7.2.6 Designing for Sharing Economy Services and Beyond**

The SEDC extended and mobilized design strategies suggested by Light and Miskelly [2015], which aim to promote different dimensions of sustainability in sharing and exchange communities: environmental, social and economic. In particular, they highlighted the importance of the community cohesion as a prerequisite to bring these strands together. Similarly, Delora and other participants discussed aspects tied to community-building while reviewing the cards. In this, they acknowledged that the **recommendations** that our cards provide, prompted

them to approach the problem from a new angle they had not yet anticipated. We have also incorporated the **User Experience** dimension as one of the cards' themes in the service of supporting community engagement early in the design process. With the rapid emergence of personal and mobile technologies, we envision that designers of future platforms for resource sharing communities and cooperatives may want to revisit the role of the UX in their value proposition. While some platforms co-ops (e.g., Stocksy, FairMondo) offer mobile-tailored (i.e., responsive) website designs to access their services, they are hardly competitive to design-driven sharing economy organizations with significant resources, such as Airbnb. Perhaps focusing on clearly communicating their commitments to cultural and community values (see Section 7.1) at different points of interaction with a platform may be beneficial to engage and retain users.

Our findings revealed that the SEDC can also be successful to surface opportunities for incorporating added privacy dimensions in the design process, known as "privacy by design" (e.g., [Cavoukian, 2013]), which is often overlooked in the early stages of product development, as highlighted by Adam. Participants also regarded that understanding the motivation behind the service is a prerequisite to start any design process. While researchers have struggled to engage designers to see the motivation behind the design briefs during the sprint [Colusso et al., 2018], we enabled participants to consider the **Motivation** theme early in the process. This worked not only to generate empathy among our participants in the given design challenge, but also to provide scaffolding for participants to detail their designs with reference to the various motives to participate in the sharing economy.

Looking at the particular distinction among profit-driven and non-profit approaches of the sharing economy [Light and Miskelly, 2015], the SEDC can productively support designers in exploring this space from different perspectives. For example, Gladys, while evaluating a profit-driven bike sharing service, mentioned that the SEDC encouraged her to reconsider the value of social ties through reciprocity, cooperation and participation. For non-profit organizations, the SEDC illustrated design opportunities to address the attendant challenges of platform co-ops – most notably to improve trust within their communities and supporting online platforms [Lampinen et al., 2015, 2013]. Following prior research highlighting specific characteristics of local and global context of the sharing economy [Light and Miskelly, 2015], our work highlights the need for future empirical research to examine the role of platform design (e.g., functionalities and their enabling mechanisms) in greater detail.

Ultimately, our findings suggested that the breadth of themes covered in the card deck may be applied to various social sharing platforms (e.g., Endomondo for

sharing personal workout data). This suggests an opportunity for future work to explore the extensibility of the cards to different, yet related areas of the sharing economy such as e-commerce, or online sharing services and apps.

#### **7.2.7 Comparing the Design Cards with Other Design Toolkits**

Similar to other design cards, the SEDC enabled creative thinking [Lucero et al., 2016; Mora et al., 2017], engaged non-experts in generating domain-specific ideas [Luger et al., 2015; Mora et al., 2017], facilitated prototyping [Halskov and Dalsgård, 2006; Lucero and Arrasvuori, 2010], and described previously unknown concepts [Colusso et al., 2018; Luger et al., 2015]. Following existing card-based approaches to facilitate the design exploration in particular application domains (e.g., Internet-of-Things [Mora et al., 2017], data privacy [Luger et al., 2015], behavioral change technologies [Colusso et al., 2018]), our design of the SEDC integrated domain-specific knowledge to inform and inspire the design process. The SEDC surfaced ongoing challenges in the emerging sharing economy design space and provided actionable recommendations on how to address them. We see this as a main differentiator across other all-purpose design toolkits (e.g., platformdesigntoolkit.com) and broader approaches to design research (e.g., qualitative contextual inquiries). The SEDC incorporated both a "what-to" and "how-to" toolkit, which offers concrete frames of references to help designers (like Gladys and Pierre, see page 190) navigate specifics of the sharing economy and to enable them to develop their ideas in this space. This can be especially beneficial to actual design teams, which often have to deal with practical challenges, such as working within limited time and resources [Roedl and Stolterman, 2013].

In contrast to many card-based design toolkits (see e.g., [Wölfel and Merritt, 2013] for a review), the SEDC provided examples of interface designs of existing successful online sharing (economy) platforms. Pierre, along with few other participants, explicitly mentioned that while such examples may limit designer's imagination, they nevertheless offer clarification and interpretation of the design goal, which can be particularly valuable for junior designers. These findings suggest an opportunity for exploring how those inspirational examples could play a role in supporting designers' creativity in professional practice [Kulkarni et al., 2014].

The SEDC can be seen akin to platform-specific interface guidelines (e.g., Apple Human Interface Guidelines), as they feature a great level of detail and can be considered as self-contained design instruments [Luger et al., 2015]. Many of our participants described and used them as "checklists", which can particularly be useful in evaluating existing sharing economy platforms and services. We

see the SEDC as translational resources [Colusso et al., 2017] that can facilitate knowledge transfer between design research and design practice [Deng et al., 2014] by offering the adequate amount of detail tailored to different stages of the design process.

#### **7.2.8 Conclusion and Future Work**

This study offers two main contributions. Firstly, it presents the Sharing Economy Design Cards and the corresponding framework for their use in a collaborative workshop. Secondly, it provides insights and findings that surfaced during the two deployment settings of the cards with 26 participants, and discusses how they help advance the design practice and design research in the context of sharing economy. Our participants have found cards useful not only in collaborative activities to create new sharing economy design concepts, but also in individual activities to provide structured design critique on the well-known existing platforms. Moreover, we demonstrated that the SEDC can be suitable for the different stages of the design process: from initial ideation, to prototyping and evaluating designs, to reporting them to the stakeholders.

Wider dissemination of the SEDC would allow us to explore their applications in industry-based projects, which have longer timespans and real-life constraints. Future research could incorporate a particular methodological lens to analyze the use of the cards in designers' creative processes such as theories of social practices. This will not only help better grounding this work in the designers' processes at their place of work, but may also offer deeper insights of the design space in the context of sharing economy. Ultimately, to further validate the usefulness of the SEDC for platform design or evaluation, one can conduct a controlled experiment where one group of designers (an experimental group) would have access to the card deck, while the other group (a control group) would not. Even though many factors could contribute to the creativity of the designers (e.g., a collaboration between peers), the yielded findings could potentially provide stronger evidence for the utility and value of our cards.

#### **7.3 Summary**

This chapter *investigates how designers can specifically support technology-mediated physical sharing practices in the context of the sharing economy* **(G3)**. In particular, reflecting upon the results of our empirical study of technology-mediated sharing practices (see Section 3.3), we elicited a set of design recommendations for

sharing economy services. Based upon these reccomendations, we developed and partially validated the Sharing Economy Design Cards, a design toolkit for sharing economy services.

At the outset, drawing on both our mapping of the sharing economy design space, as well as a comprehensive account of the commonalities and differences between digital and physical sharing practices (see Section 3.3.3), we formulated a set of design implications for devising novel sharing economy services and platforms. Specifically, we offered design strategies to *leverage the dual nature* of the shared content (i.e., a physical artifact and corresponding layers of digital metadata) in the sharing economy, we provided ideas how to *adjust levels of selfdisclosure* throughout the course of a sharing transaction, and we urged platform designers to *actively communicate* pro-social benefits of the sharing economy services they are building. Furthermore, we emphasized the importance of the nuanced *mechanisms to improve trust* within resource sharing communities and their supporting online platforms, as well as discussed the value of *operationalizing sharing triggers* to improve user experience with a sharing economy service.

Drawing on these design implications, we developed the Sharing Economy Design Cards. The cards can be seen as a "what-to" and "how-to" toolkit that provides domain-specific recommendations for UX and service designers to aid the developement of their ideas in the context of the sharing economy. The deck consists of 24 cards that are organized into five key design themes – **Content**, **Audience**, **Motivations**, **Privacy and Trust**, and **User Experience**. Each card is divided into seven sections (see Figure 7.1): (1) a card's theme; (2) a leading question; (3) a design goal; (4) searchable keywords; (5) an actionable recommendation; (6) a detailed description; and (7) an UI example from an existing service. We deployed our design cards with 26 participants and discussed how they can be used in individual activities (e.g., to facilitate structured design critique akin to an expert evaluation of existing sharing economy services), as well as in collaborative workshops (e.g., to create original sharing economy design concepts in a group setting). We additionally developed and field-tested a corresponding design methodology for the cards' use in a collaborative workshop. Our findings suggested that the cards, owing to their thematic composition and their structure, can effectively support both the divergence steps of the design process (e.g., exercise designers creativity based on cards' broad design goals and themes), as well as better enabling convergence activities (e.g., refine a specific design concept through cards' action-driven recommendations). In particular, we demonstrated how the cards can be a versatile design tool suitable for the different stages of the design process: from initial ideation and sketching, to prototyping and evaluating designs, to communicating and advocating them to

the stakeholders, to identifying and reporting design flaws in existing sharing economy platforms. Ultimately, the cards were not only instrumental in creating new design material to inform decision-making in a group setting, but also enabled speculation on future-looking opportunities of their use beyond devising sharing economy services.

In the next chapter, we reflect upon the research contributions of this thesis by situating the findings from this chapter and others in the context of our original research goals. We also outline the limitations of our approach and discuss directions for future work.

# **Chapter 8 Conclusions and Future Work**

This dissertation explored the design space of novel technology-mediated sharing practices in two emergent sharing domains: (1) the domain of personal activity tracking; (2) the domain of sharing economy services. The goal of this final chapter is to offer concluding remarks on the work we conducted in this thesis. We first provide summaries of the research problems we addressed and discuss the completed research goals that form our research contributions. Furthermore, we outline the limitations of our approach. Ultimately, we describe two future avenues for interaction design research in the context of the sharing economy that can build upon this dissertation.

In Chapter 1, we identified the main motivation for our work – an overarching problem of understanding how the design of networked and interactive technologies could adequately address the challenge of information oversharing and the challenge of under-sharing of physical resources in two aforementioned domains. In order to approach this challenge, we formulated three research problems that we addressed in our thesis:

#### **8.1 Contribution Summary**

The main goal of our research was to understand current practices of sharing personal digital and physical possessions, and to uncover corresponding end-user needs and concerns across novel technology-mediated sharing practices, in order to map the design space for user experience design to support emergent and future sharing needs.

In this thesis, we addressed the three aforementioned problems with the completion of the corresponding research goals (G1-G3). We outline those goals below and summarize the steps we took to attend to them while describing their particular research contributions to the field of HCI, interaction design research, and, more specifically the design technology for sharing.

#### (G1) **Provide a comprehensive account of common digital sharing practices stemming from the advent of personal activity tracking.**

We achieved this goal by conducting an online questionnaire of 246 individuals to examine their novel content sharing practices, stemming from personal activity tracking, and contextual interviews with 45 participants to elicit their sharing needs and concerns in the prototypical context of outdoor sports. We analyzed the findings using quantitative and qualitative analysis approaches and synthesized the insights with the related work. The completion of **G1** presents two major research contributions:

— *A descriptive mapping of novel content sharing practices online*. In Chapter 4, we presented peoples' practices of sharing (1) music preferences and playlists; (2) travel plans and trip details; (3) details of physical exercises and sports activity; (4) digital representation and contextual metadata about real-world items such as rooms and vehicles; (5) virtual artifacts in video games and virtual social worlds and (6) personal culinary and dietary preferences. We systematically identified and compared content items that are being shared across various audiences, as well as elicited the examples of actual online services that enable sharing of novel types of content. We subsequently illustrated the limitations of these services and tools, and outlined the common privacy concerns that frame novel content sharing practices. Ultimately, we empirically extracted a set of factors that influence device preference when accessing supporting sharing services, and revealed that desktop interfaces of those services in contrast to their mobile counterparts are often considered more efficient and easy to use – both for sharing, and access control tasks (i.e., privacy).

— *A set of insights on supporting digital sharing practices of co-located leisure skiers*. In Chapter 5, we examined in-depth how mobile and wearable technologies

could support digital sharing practices of leisure skiers. We initially identified their information sharing needs before, during and after the activity. We discovered that skiers often share location information, media content and reference information about ski resorts (e.g., amount and types of hazards in the area) within co-located groups. Following contextual and participatory design processes, we extracted the design requirements for an interactive system to support skiers sharing practices and subsequently designed, developed and deployed SkiAR, a wearable augmented reality system for sharing personalized content on ski resort maps. We offered prospective critical reflections on how the SkiAR system (a) supported skiers' group planning and decision-making in situ; (b) afforded adequate interactions utilizing envisioned wearable high-tech skiwear; (c) enabled collection and sharing activity-related content within a group. Finally, we introduced two interaction design concepts for in situ content sharing systems that could support decision-making encounters within and beyond the context of outdoor sports: (1) *points-of-interaction* i.e., the location where actual group decisions are taken, and (2) the *temporal aspects of interactions*, the fact that those interactions are often time-constrained.

The completion of **G1** also presents an additional, yet still important, contribution:

— *A proof-of-concept for remotely-located sharers*. In Chapter 5, in order to further our understanding of the variety of novel shared content types stemming from personal activity tracking, we looked at biophysical and emotional data. Nowadays, this data can be relatively easily gathered from the widespread personal wearable devices (e.g., fitness trackers, smartwatches) and, subsequently, shared online. We selected the context of movie-viewing with distance-separated families/couples to meaningfully leverage sharing of these types of data. We designed and developed Movie+, an interactive prototype that allows one to create and share emotional fingerprints of a recently viewed video clip or a movie with family members and friends. We offered a set of considerations for a prototype's field deployment to uncover the social end experiential effects of sharing emotional fingerprints.

#### (G2) **Describe nuanced design characteristics for interactive technologies to support physical sharing practices in the context of the sharing economy.**

We completed this goal by conducting two field studies. In the first study, we employed the empirical sampling method and analyzed individual practices of sharing everyday purchases of 71 participants. In the second study, we conducted

an ethnographically-inspired qualitative inquiry into tool sharing practices of one resource sharing cooperative with a view to eliciting their ongoing organizational challenges and informing the design of an interactive system to approach those challenges. We interviewed 16 active co-op members and employed an open coding technique to analyze the results and synthesized them within the related work. The completion of **G2** presents two major research contributions:

— *A descriptive account of sharing practices of everyday purchases.* In Chapter 6, stemming from a month-long diary study of everyday purchase sharing routines, we identified the most shared categories of everyday purchases. We illustrated that sharing purchases typically happens within domestic environments among close family members and friends. In addition to that, we computationally determined that overall purchase satisfaction positively affects its sharing. Delving further into this relationship, we elicited motivational and experiential aspects of sharing purchases spanning hedonic, eudaimonic and environmental factors of everyday consumption. Ultimately, we articulated a set of user experience design considerations for future persuasive technologies that aim to support purchase sharing.

— *A set of design recommendations for interactive technologies to support resource sharing communities.* In Chapter 6, we established a case study with the Vancouver Tool Library (VTL), a tool sharing cooperative. We identified the coop's three emergent organizational challenges: (1) the large degree of members' anonymity, (2) poor visibility of members' work, and (3) the lack of accountability for shared resources. We empirically demonstrated that those challenges can be partially addressed through capturing and sharing members' tool-use experiences. We designed and developed Roaming Objects, a mobile application that afforded the creation and sharing of such experiences. We subsequently deployed the Roaming Objects app at the VTL for two months to elicit a range of self-reflections across members of the VTL on how digital narratives could shape their reactions to shared objects (e.g., tools) and to the broader social tool-sharing organization. Drawing on the field deployment, we elicited a set of design recommendations to support physical sharing practices within resource-sharing communities. Namely, (1) the *progressive self-disclosure* technique may have a potential to de-anonymize the community membership; (2) accrued *experiential histories of use* not only increased visibility of largely unseen members' practices, but also became useful indicators for timely tools maintenance and for required inventory updates (thus helping in overall accountability of the tools among volunteers and members); and (3) *dynamic thing-story assemblages* opened opportunities for adapting Roaming Objects beyond tool-sharing communities for virtually any resource sharing collectives where physical things change many hands over time.

— *A proof-of-concept for supporting informal economies of personal artifacts.* Building upon the design considerations from the deployment of the Roaming Objects system at the VTL, we looked beyond resource sharing organizations and explored the context of informal economies of personal artifacts (e.g., sharing/ renting a pair of skies through an online platform to an unknown peer). Following the review of the relevant literature, we identified two attendant challenges of such online communities: (1) issues of trust within the community members and the supporting online platforms and (2) difficulties with dealing with a growing number of intermediaries (e.g., a payment processing company, an insurance, a bank), especially when the goods are not adequately delivered/returned. For this purpose, we designed and developed "Just Share It", a mobile application that, firstly, aims to engender trust within the community and the online platform through implementing a reputation review mechanism on a transparent and immutable blockchain ledger, and, secondly, offers a prospective solution for disintermediation by utilizing an escrow property of emergent smart contracting technologies. We discussed the future-looking opportunities for a field-deployment of our system and reflected upon the use of blockchain ecosystems as a resource for the design technologies within the context of the sharing economy.

#### (G3) **Investigate how designers can specifically support technology-mediated physical sharing practices in the context of the sharing economy.**

We completed this goal by conducting a literature survey of technology-mediated sharing practices, 16 expert interviews on contemporary sharing economy services, and a set of qualitative studies (individual interviews and creative collaborative workshops) with a total of 26 designers and sharing economy domain experts. The completion of **G3** presents two major research contributions:

— *A mapping of the design space between physical and digital sharing practices.* In Chapter 2, we systematically reviewed prior work that broadly covered various technology-mediated sharing practices spanning from file sharing to sharing physical things in the context of the sharing economy. We additionally recruited 16 design practitioners and sharing economy domain experts for qualitative interviews to discuss specific socio-technical and design challenges of contemporary sharing economy services. In Chapter 3, based upon both the synthesis from our empirical review of the literature, and experts' reflections and reactions, we elicited five key design themes of technology-mediated sharing practices: (1) the diversity of shared content; (2) audience management; (3) motivations to share; (4) privacy and trust issues; and (5) user experience requirements. These key

themes, along with detailed sub-themes (see Figure 3.3) constitute 13 sharing dimensions that can be used as a common frame of reference for researchers and designers who are investigating this emergent space. Using these dimensions, we outlined nuanced commonalities and differences among the digital and physical sharing spheres.

— *A set of design implications, a design toolkit, and a method for the creation and evaluation of sharing economy services.* In Chapter 7, building upon the dichotomy between physical and digital sharing practices identified in Chapter 3, we subsequently formulated a set of design implications for devising novel sharing economy services and platforms. Drawing on the elicited design implications, we designed the Sharing Economy Design Cards, a "what-to" and "how-to" design toolkit for the sharing economy. We also developed a corresponding design methodology for the card's use in collaborative settings. We then partially validated our cards with 26 design practitioners and sharing economy domain experts in individual and group activities. We articulated that our cards can be seen as a versatile tool to help designers to navigate specifics of the sharing economy, and to develop their ideas in this space by offering the adequate amount of detail needed at both divergence and convergence steps of the design process – from initial ideation and sketching, to prototyping and evaluating designs, to communicating and advocating them to the stakeholders, to evaluating existing sharing economy platforms. On the whole, we highlighted the cards' usefulness not only in collaborative activities to create new sharing economy design concepts, but also in individual activities to provide a structured design critique on the well-known existing platforms. Ultimately, the cards enabled speculation on future-looking opportunities of their use beyond devising sharing economy services.

#### **8.2 Limitations**

In this section, we would like to acknowledge several limitations of our research.

The first limitation relates to the malleable concept of *sharing* that often means too many different things and touches various aspects of our lives (see Chapter 2). Therefore, this polysemic nature of the phenomenon makes it hard to generalize our findings. Drawing on the work of the media and communication scholarship (e.g., [John, 2017; Kennedy, 2015]), in Chapter 3, we framed sharing based upon its communicative and distributive logics, as well as upon the medium where the sharing takes place – digital ephemera or the real world. We contextualized this phenomenon within two emergent sharing domains: (1) the domain of personal activity tracking and (2) the domain of sharing economy services. We argued

how these two domains are interconnected owing to a mediating online platform that often governs the interactions among a sharer and a sharee, and the *dual* nature of the shared content within sharing economy services (see Chapter 7). We subsequently presented how the challenges of one domain are inherently related to the other one, and how they can be characterized within five key design concepts/ themes – (1) shared **content**, (2) target **audiences**, (2) **motivations** to share, (3) aspects of **privacy and trust**, (5) and **user experience**. Future research should look at how these concepts could be situated, adapted, and extended in newly emergent sharing practices, for example, sharing digital possessions in virtual social worlds, or machine-to-machine information sharing in an IoT environment, as well as in "traditional" offline sharing practices such as of sharing physical things within neighbors or sharing emotions between people at large.

Secondly, while throughout our thesis we looked at the different sharing *practices*, we acknowledge the moderate use of the actual theories of social practices described in Chapter 3. These theories were fundamental in framing our research questions and informing the design of our empirical studies, albeit we have adopted their ideas only partially. In our thesis, we drew upon the work of Kennedy [2018], who offered an understanding of sharing practice as a composition of three inter-related elements: *materiality*, *symbolic values* and *competences* (see Chapter 3). These elements helped to form the basis of our core sharing questions and informed the above-mentioned key design concepts, namely (a) shared **content** that addressed the question "What is being shared?" exploring the *materiality* element; (b) **motivations** to share that exploit the *symbolic values* component of a practice by eliciting sharing meanings and aspirations and attending to the question "Why sharing takes place?"; and (c) **user experience** inquiring "How sharing takes place?" speaking to the *competences*. What is more, we offered an interpretation of how the elements from Kennedy's framework [2018] could be adapted beyond networked cultures towards technology-mediated sharing practices in the context of collaborative consumption. Specifically, we provided a common frame of reference for design research and design practice through systematically mapping the sharing economy design space, and formulated a set of specific design recommendations (e.g., in the form of the Sharing Economy Design Cards) for devising new instances of sharing economy services and platforms. Leveraging these theoretical underpinnings of sharing, we then designed, developed and deployed several technological prototypes to partially validate and extend our assumptions about sharing through a set of field studies.

In addition to that, we followed a practice-oriented approach to research exploring everydayness and ubiquity of sharing practices [Kennedy, 2015], rather than explicitly engaging in a prescriptivist debate about what counts as sharing and

what is not. In turn, HCI researchers demonstrated that in generative approaches to design *a practice* could be used as a unit of analysis [Wakkary et al., 2013] as well as a unit of design [Kuijer et al., 2008]. Note that in these approaches people have a peripheral role as carriers of practice. Consequently, we made an informed decision to follow user-centered design approach, instead of designing for practices, in order to ensure that people remain at the center of a design process and their sharing needs and concerns are adequately accounted for.

The third limitation relates to the choice of the methodology. The qualitative research approaches that we widely employed in our thesis have an inherent limitation of being hard to generalize to different populations. Therefore, despite the rich and descriptive accounts we developed within two emergent sharing domains, our findings should be interpreted with caution. Nevertheless, the very nature of these methods allowed us to describe in great detail and depth peoples' sharing practices within a given context. In addition to that, in Chapters 4 and 5, we complemented our findings with quantitative research methods in order to determine causal relationships between different elements that constitute sharing in their respective contexts. Furthermore, responding to the call of Dillahunt et al. [2017], we developed several interactive prototypes to support sharing practices of individual and groups within two emergent sharing domains leveraging a system-building tradition of HCI. Nonetheless, more varied methods of research are needed to establish a holistic understanding of technology-mediated sharing practices within the context of the sharing economy.

Ultimately, a further limitation of this work is related to the diversity and the composition of participants in our studies. The work presented in this thesis often recruited young and tech-savvy participants from middle-class backgrounds who live and work in an industrialized Western country (mostly from North America and Europe). On the one hand, these populations represent the actual users of technology-mediated sharing services and tools well, on the other hand, it is important to acknowledge that sharing practices and routines could be different in various cultural, geographic and demographic contexts. Therefore, future research should look at the technology-mediated sharing practices of participants with different socio-economic backgrounds, ages, and beyond Western culture.

#### **8.3 Future Work**

This dissertation presents a building block for researchers and designers who interested in further exploring technology-mediated sharing practices. Throughout this dissertation, we suggested new areas for future research and practice

initiatives in the HCI and interaction design communities. In particular, in what immediately follows, we outline two opportunities for future work in the context of the sharing economy.

#### **8.3.1 Local Economies of Personal Artifacts**

Building upon the findings from our study of tool-sharing practices in the Vancouver Tool Library (see Section 6.2), we outlined the need to further support the design of platforms and tools for non-profit approaches to the sharing economy (e.g., local resource sharing associations and grassroots initiatives) in order to ensure the sustainable development and growth of their respective communities. Specifically, we see the value in exploring how information technologies can support the sharing of underutilized personal physical artifacts (e.g., tools, household items, sports equipment) within local communities.

Throughout our research on alternative models of the sharing economy, we came across a sharing community Pumpipumpe (pumpipumpe.ch), which was founded in Bern (Switzerland) in 2012. The community provides a set of stickers that can be put on a mailbox to let neighbors know what household items one is willing to share. Being a "low-tech" solution, the service does not specify how the sharing of those items would be arranged – it is up to the individuals to agree upon terms of use and arrangements for an item's return. The pre-defined images on the stickers vary from common household items (e.g., a bike-pump) and tools (e.g., a drill), to rarely used kitchen appliances (e.g., a pasta maker), to typical Swiss cookware such as fondue sets. One can design their own sticker as well, in case none from the standard set match. Currently, its online service offers only a simple search interface, including an online map of participating households. There is no monetary compensation explicitly designed and endorsed by the platform.

In 2014, Pumpipumpe formalized their legal status in Switzerland as a nonprofit association. The goal of the association is to provide awareness of conscious re-use of peoples' underutilized personal possessions while supporting face-to-face encounters of neighbors. The association is run entirely by volunteers to support day-to-day operations of the association. All revenues collected from the sale of the sticker-sets (5 Swiss Francs/Euros for a set of 40) covers the printing and shipping costs. This rather simple idea quickly gained popularity outside Switzerland. Now, nearly 20 000 households participate worldwide. Pumpipumpe is an interesting example of a sharing economy service that promotes trust, encourages sustainable consumption, facilitates social encounters and fosters the development of local communities.

Nonetheless, when we initially approached the association in 2018, we quickly realized that they have very little knowledge of the actual practices, needs, and concerns of the participating individuals and households. Apart from the name, the address and the type of ordered stickers, the community membership was largely unknown and anonymous to the association. As a result of that, the association faced growing concerns regarding their future activities in order to adequately support and serve their members' needs.

Therefore in our future work, we would like to create a comprehensive ethnographic account of physical sharing practices of local economies of personal artifacts in a prototypical resource sharing community, such as Pumpipumpe. In particular, we would like to explore *what* people are currently sharing/renting from their personal possessions, and understand the conditions and circumstances of *how* these exchanges are performed. In addition to that, we would like to compare and contrast these sharing practices and routines with our field-work conducted at the Vancouver Tool Library (VTL), see Chapter 6.

We expect that resource sharing practices within neighbors would be different from the ones in the VTL, owing to the following important distinctions among them: (a) the individual or family-ownership of household items in contrast to collective ownership in the VTL; (b) the processes of borrowing items are selforganized in contrast to the established practices at the VTL (e.g., tools check-out at a counter with a presence of a volunteer); (c) the underlying meaning of sharing resources (e.g., tools) in the neighborhoods generally aimed towards straightening social connection and community resilience instead of various motives of participation in well-established cooperatives such as the VTL (e.g., to learn a new tool, engage in a personal project); (d) intricate use of ICT within informal resource sharing communities in comparison to the centralized infrastructure (e.g., inventory software) at the VTL.

Ultimately, through contextual and participatory design approaches, we will collect a set of user requirements for a local sharing economy platform in order to support the community's operations and address their emergent challenges.

#### **8.3.2 Trust Accrual in Online Resource Sharing Communities**

A further research avenue that immediately appeared from our dissertation is the growing concerns of trust within the peers and the supporting online platforms in the context of the sharing economy in general and within the online rental or swapping platforms for physical goods in particular. In Section 6.3, we described the design of a mobile sharing system to connect lenders and borrowers using blockchain-based technologies. We argued that these technologies may

help (1) to engender trust within an online exchange platform by keeping an immutable record of peers' reputations/ratings on transparent distributed ledger and (2) to reduce the number of intermediaries when dealing with potential disputes. For example, smart contracting technologies could offer a platform for conflict resolution in order to settle occurred disagreements between a lender and a borrower regarding the state of a shared item (e.g., broken returns).

We envision deploying our system into an existing online resource sharing community (e.g., Peerby) in order to validate our assumptions. This will not only allow us to elicit aspects of perceived trust within a sharing platform and to examine the role of blockchain technologies in trust accrual, but also to identify challenges and opportunities related to the experiences of the use of a blockchainbased system in the context of the sharing economy. In this effort, we particularly like to set the following questions: "How can technology interventions facilitate or inhibit trust within a community and within a supporting platform?", "What are users' perceptions of trust enabled by the smart contracting technologies within a sharing economy community?" Ultimately, we hope this work inspires future research to look at how blockchain-based technologies can further support physical sharing practices in an IoT future, where everyday things (e.g., an IoTenabled pair of skis) are controlled by a machine agent, and thus have their own decision-making capabilities and power to execute smart contracts.

#### **8.4 Final Remarks**

This dissertation supported the design for technology-mediated sharing practices using empirical research methods. It has identified the set of differences and commonalities between sharing digital and physical artifacts. It has also indepth examined and articulated novel sharing practices and routines within two domains: (1) the personal activity tracking and (2) the sharing economy. What is more, we designed, developed and field-tested several technological prototypes to elicit how interactive technologies may support the novel sharing practices in those domains with the view to informing the design of tools and services to address emergent and future peoples' sharing needs. In addition to that, we offered a design toolkit and a method for the sharing economy targeted design practitioners to assess and improve current and future sharing services and to engender user experience with such systems.

Ultimately, we discussed the complexity of the sharing phenomenon and illustrated the existence of an obscure boundary between digital and physical sharing, drawing upon the ideas from the social sciences. Our work was informed by scholarship in several domains, including consumer behavior research, communication and media sciences, sociology, privacy research, human-computer interaction, and interaction design. Therefore, we believe that taking this cross-disciplinary perspective, this thesis contributed new empirical knowledge on the design technologies for sharing. We hope that this dissertation can be seen as a building block for the HCI and interaction design researchers and practitioners to further explore intricate nuances of sharing across digital ephemera and the real world. We also believe that this dissertation provided a set of necessary references (e.g., the key design themes for technology-mediated sharing practices) to allow future research to investigate how new technologies, such as augmented and virtual realities, can further shape our perceptions and practices of everyday sharing among people and ubiquitous computational artifacts.

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## **Appendix A**

## **Materials from Technology-Mediated Sharing Literature Survey**