[with added adjective rating as an 11th question]{}. []{data-label="fig:sus_adjective"}](images/sus/sus_adjective_rating "fig:"){width="\linewidth"}\

System usability scale () rating

### Semantic Differential  {#sec:questionnaires_attrakdiff}

A semantic differential is a technique for the measurement of meaning as defined by Osgood et al. [@osgood1952nature; @osgood1957measurement]. Semantic differentials are based on the theory, that the implicit anticipatory response of a person to a stimulus object is regarded as the object’s meaning. Since these implicit responses themselves cannot be recorded directly, more apparent responses like verbal expressions have to be considered [@mehrabian1974approach; @fishbein1975belief]. These verbal responses have to be sensitive to and maximally dependent on meaningful states while independent from each other [@osgood1957measurement]. Hassenzahl et al. [@hassenzahl2003attrakdiff; @hassenzahl2000hedonic] defined a set of $28$ pairs of verbal expressions suitable to represent a subject’s opinion on the hedonic as well as pragmatic quality (both aspects of perception) and attractiveness (an aspect of assessment) of a given interactive system separately [@hassenzahl2001effect]. During evaluation, the pairs of complementary adjectives are clustered into four groups, each associated with a different aspect of quality. Pragmatic quality () is defined as the perceived usability of the interactive system, which is the ability to assist users to reach their goals by providing utile and usable functions [@hassenzahl2008user]. 