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User Interface Design


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User Interface Design

  1. 1. OBJECTIVES When you finish this chapter, you will be able to:  Explain the concept of user interface design and human- computer interaction, including basic principles of user- centered design  List user interface design guidelines  Describe user interface components, including screen elements and controls  Discuss output design and technology issues  Design effective source documents  Explain input design and technology issues  Discuss guidelines for data entry screen design  Use input masks and validation rules to reduce input errors  Describe output and input controls and security
  2. 2. What is a User Interface?  A user interface (UI) describes how users interact with a computer system, and consists of all the hardware, software, screens, menus, functions, output, and features that affect two-way communications between the user and the computer.
  3. 3. Evolution of the User Interface
  4. 4. User Rights 1. Perspective: The user always is right. If there is a problem with the use of the system, the system is the problem, not the user. 2. Installation: The user has the right to install and uninstall software and hardware systems easily without negative consequences. 3. Compliance: The user has the right to a system that performs exactly as promised. 4. Instruction: The user has the right to easy-to-use instructions (user guides, online or contextual help, and error messages) for understanding and utilizing a system to achieve desired goals and recover efficiently and gracefully from problem situations. 5. Control: The user has the right to be in control of the system and to be able to get the system to respond to a request for attention. 6. Feedback: The user has the right to a system that provides clear, understandable, and accurate information regarding the task it is performing and the progress toward completion. 7. Dependencies: The user has the right to be informed clearly about all systems requirements for successfully using software or hardware. 8. Scope: The user has the right to know the limits of the system’s capabilities. 9. Assistance: The user has the right to communicate with the technology provider and receive a thoughtful and helpful response when raising concerns. 10. Usability: The user should be the master of software and hardware technology, not vice versa. Products should be natural and intuitive to use.
  5. 5. Human-Computer Interaction  Human-computer interaction (HCI) describes the relationship between computers and people who use to perform their jobs, like the worker shown in Figure 8-5. FIGURE 8-5 HCI is essential to employee productivity, whether the work is done in a traditional office setting, or on a construction site like the one shown here.
  6. 6. Principles of User-Centered Design 1. Understand the Business 2. Maximize Graphical Effectiveness 3. Think Like a User 4. Use Models and Prototypes 5. Focus on Usability 6. Invite Feedback 7. Document Everything
  7. 7. Designing the User Interface 1. Design a transparent interface. a. Facilitate the system design objectives, rather than calling attention to the interface. b. Create a design that is easy to learn and remember. c. Design the interface to improve user efficiency and productivity. d. Write commands, actions, and system responses that are consistent and predictable. e. Minimize data entry problems. f. Allow users to correct errors easily. g. Create a logical and attractive layout.
  8. 8. 2. Create an interface that is easy to learn and use. a. Clearly label all controls, buttons, and icons. b. Select only those images that users can understand easily, and provide on-screen instructions that are logical, concise, and clear. c. Show all commands in a list of menu items, but dim any commands that are not currently available. d. Make it easy to navigate or return to any level in the menu structure.
  9. 9. 3. Enhance user productivity. a. Organize tasks, commands, and functions in groups that resemble actual business operations. b. Create alphabetical menu lists or place the selections used frequently at the top of the menu list. c. Provide shortcuts so experienced users can avoid multiple menu levels. d. Use default values if the majority of values in a field are the same. e. Use a duplicate value function that enables users to insert the value from the same field in the previous record. f. Provide a fast-find feature that displays a list of possible values as soon as users enter the first few letters. g. Use a natural language feature that allows users to type commands or requests in normal English phrases.
  10. 10. 4. Make it easy for users to obtain help or correct errors. a. Ensure that help is always available. b. Provide user-selected help and context-sensitive help. c. Provide a direct route for users to return to the point from where help was requested. d. Include contact information. e. Require user confirmation before data deletion and provide a method of recovering data that is deleted inadvertently. f. Provide an Undo key or a menu choice that allows the user to eradicate the results of the most recent command or action. g. When a user-entered command contains an error, highlight the erroneous part and allow the user to make the correction without retyping the entire command. h. Use hypertext links to assist users as they navigate through help topics.
  11. 11. 5. Minimize Input Data a. Create input masks, which are templates or patterns that make it easier for users to enter data. b. Display event-driven messages and reminders. c. Establish a list of predefined values that users can click to select. d. Build in rules that enforce data integrity.
  12. 12. 6. Provide Feedback to Users a. Display messages at a logical place on the screen, and be consistent. b. Alert users to lengthy processing times or delays. c. Allow messages to remain on the screen long enough for users to read them. d. Let the user know whether the task or operation was successful or not. e. Provide a text explanation if you use an icon or image on a control button. f. Use messages that are specific, understandable, and professional.
  13. 13. 7. Create an Attractive Layout and Design a. Use appropriate colors to highlight different areas of the screen; avoid gaudy and bright colors. b. Use special effects sparingly. c. Use hyperlinks that allow users to jump to related topics. d. Group related objects and information. e. Screen density is important. f. Display titles, messages, and instructions in a consistent manner and in the same general locations on all screens. g. Use consistent terminology. h. Ensure that commands always will have the same effect. i. Ensure that similar mouse actions will produce the same results throughout the application. j. When the user enters data that completely fills the field, do not move automatically to the next field.
  14. 14. 8. Use Familiar Terms and Images a. Remember that users are accustomed to a pattern of red = stop, yellow = caution, and green = go. Stick to that pattern and use it when appropriate to reinforce onscreen instructions. b. Provide a keystroke alternative for each menu command, with easy-to-remember letters, such as File, Exit, and Help. c. Use familiar commands if possible, such as Cut, Copy, and Paste. d. Provide a Windows look and feel in your interface design if users are familiar with Windows-based applications. e. Avoid complex terms and technical jargon; instead, select terms that come from everyday business processes and the vocabulary of a typical user.
  15. 15. Good user interface design is based on a combination of ergonomics, aesthetics, and interface technology. ERGONOMICS describes how people work, learn, and interact with computers; AESTHETICS focuses on how an interface can be made attractive and easy to use; and INTERFACE TECHNOLOGY provides the operational structure required to carry out the design objectives.
  16. 16. Add Control Features The designer can include many features, such as menu bars, toolbars, dialog boxes, text boxes, toggle buttons, list boxes, scroll bars, drop-down list boxes, option buttons, check boxes, command buttons, and calendar controls, among others.
  17. 17.  The menu bar at the top of the screen displays the main menu options.  A command button initiates an action such as printing a form or requesting help.  A dialog box allows a user to enter information about a task that the system will perform.  A text box can display messages or provide a place for a user to enter data.  A toggle button is used to represent on or off status — clicking the toggle button switches to the other status.  A list box displays a list of choices that the user can select. If the list does not fit in the box, a scroll bar allows the user to move through the available choices.
  18. 18.  A drop-down list box displays the current selection; when the user clicks the arrow, a list of the available choices displays.  An option button, or radio button, represents one choice in a set of options. The user can select only one option at a time, and selected options show a black dot.  A check box is used to select one or more choices from a group. Selected options are represented by a checkmark or an X.  A calendar control allows the user to select a date that the system will use as a field value.
  19. 19. Screen design requires a sense of aesthetics as well as technical skills. You should design screens that are attractive, easy to use, and workable. You also should obtain user feedback early and often as the design process continues. The opening screen is especially important because it introduces the application and allows users to view the main options. When designing an opening screen, you can use a main form that functions as a switchboard. A switchboard uses command buttons that enable users to navigate the system and select from groups of related tasks.
  20. 20. Output Design Before designing output, ask yourself several questions:  What is the purpose of the output?  Who wants the information, why is it needed, and how will it be used?  What specific information will be included?  Will the output be printed, viewed on-screen, or both? What type of device will the output go to?  When will the information be provided, and how often must it be updated?  Do security or confidentiality issues exist?
  21. 21. Types of Reports  DETAIL REPORTS. A detail report produces one or more lines of output for each record processed. Each line of output printed is called a detail line.
  22. 22.  EXCEPTION REPORTS. An exception report displays only those records that meet a specific condition or conditions.
  23. 23.  SUMMARY REPORTS. Upper-level managers often want to see total figures and do not need supporting details. A sales manager, for example, might want to know total sales for each sales representative, but not want a detail report listing every sale made by them. In that case, a summary report is appropriate.
  24. 24. Designing a Report 1. You should prepare a sample report, called a mock-up, or prototype, for users to review. The sample should include typical field values and contain enough records to show all the design features. Depending on the type of printed output, you can create a Word document or use a report generator to create mock-up reports. 2. After a report design is approved, you should document the design by creating a report analysis form, which contains information about the layout, fields, frequency, distribution, data security considerations, and other issues.
  26. 26. Output Technology 1. Internet – Based Information Delivery 2. E-mail 3. Blogs 4. Instant Messaging 5. Wireless Devices 6. Digital Audio, Images, and Video 7. Podcasts 8. Automated Facsimile Systems 9. Computer Output to Microfilm (COM) 10. Computer Output to Digital Media
  27. 27. 11. Specialized Forms of Output An incredibly diverse marketplace requires many forms of specialized output and devices such as these:  Portable, Web-connected devices that can run applications, handle multimedia output, and provide powerful, multipurpose communication for users  Retail point-of-sale terminals that handle computer-based credit card transactions, print receipts, and update inventory records  Automatic teller machines (ATMs) that can process bank transactions and print deposit and withdrawal slips  Special-purpose printers that can produce labels, employee ID cards, driver’s licenses, gasoline pump receipts, and, in some states, lottery tickets  Plotters that can produce high-quality images such as blueprints, maps, and electronic circuit diagrams  Electronic detection of data embedded in credit cards, bank cards, and employee identification cards
  28. 28. Input Design  The objective of input design is to ensure the quality, accuracy, and timeliness of input data.  The term garbage in, garbage out (GIGO), is familiar to IT professionals, who know that the best time to avoid problems is when the data is entered.  Good input design requires attention to human factors as well as technology issues.
  29. 29. Source Documents and Forms  A source document collects input data, triggers or authorizes an input action, and provides a record of the original transaction.  Source documents generally are paper-based, but also can be provided online. Either way, the design considerations are the same.  Good form layout makes the form easy to complete and provides enough space, both vertically and horizontally, for users to enter the data.  A form should indicate data entry positions clearly using blank lines or boxes and descriptive captions.
  30. 30. Source Document Zones  The heading zone usually contains the company name or logo and the title and number of the form.  The control zone contains codes, identification information, numbers, and dates that are used for storing completed forms.  The instruction zone contains instructions for completing the form.  The main part of the form, called the body zone, usually takes up at least half of the space on the form and contains captions and areas for entering variable data.  If totals are included on the form, they appear in the totals zone.  Finally, the authorization zone contains any required signatures.
  31. 31. Data Entry Screens  Data capture uses an automated or manually operated device to identify source data and convert it into computer-readable form.  Examples of data capture devices include credit card scanners and bar code readers.  Data entry is the process of manually entering data into the information system, usually in the form of keystrokes, mouse clicks, touch screens, or spoken words.  The most effective method of online data entry is form filling, in which a blank form that duplicates or resembles the source document is completed on the screen. The user enters the data and then moves to the next field.
  32. 32. The following guidelines will help you design data entry screens that are easy to learn and use. 1. Restrict user access to screen locations where data is entered. 2. Provide a descriptive caption for every field, and show the user where to enter the data and the required or maximum field size. 3. Display a sample format if a user must enter values in a field in a specific format. 4. Require an ending keystroke for every field. 5. Do not require users to type leading zeroes for numeric fields.
  33. 33. 6. Do not require users to type trailing zeroes for numbers that include decimals. 7. Display default values so operators can press the enter key to accept the suggested value. 8. Use a default value when a field value will be constant for successive records or throughout the data entry session. 9. Display a list of acceptable values for fields, and provide meaningful error messages if the user enters an unacceptable value. 10. Provide a way to leave the data entry screen at any time without entering the current record.
  34. 34. 11. Provide users with an opportunity to confirm the accuracy of input data before entering it by displaying a message such as, Add this record? (Y/N). 12. Provide a means for users to move among fields on the form in a standard order or in any order they choose. 13. Design the screen form layout to match the layout of the source document. 14. Allow users to add, change, delete, and view records. 15. Provide a method to allow users to search for specific information, as shown in Figure 8-33.
  35. 35. Input Masks  Use input masks, which are templates or patterns that restrict data entry and prevent errors.
  36. 36. A DATA VALIDATION RULE improves input quality by testing the data and rejecting any entry that fails to meet specified conditions. You can design at least eight types of data validation rules. For example: 1. A sequence check is used when the data must be in some predetermined sequence. 2. An existence check is used for mandatory data items. 3. A data type check tests to ensure that a data item fits the required data type. 4. A range check tests data items to verify that they fall between a specified minimum and maximum value. When the validation check involves a minimum or a maximum value, but not both, it is called a limit check. 5. A reasonableness check identifies values that are questionable, but not necessarily wrong. 6. A validity check is used for data items that must have certain values. 7. A combination check is performed on two or more fields to ensure that they are consistent or reasonable when considered together. 8. Batch controls are totals used to verify batch input.
  37. 37. Input Technology
  38. 38. Batch Input  Using batch input, data entry usually is performed on a specified time schedule, such as daily, weekly, monthly, or longer.  For example, batch input occurs when a payroll department collects time cards at the end of the week and enters the data as a batch.  Another example is a school that enters all grades for the academic term in a batch.
  39. 39. Online Input  Although batch input is used in specific situations, most business activity requires online data entry.  A popular online input method is source data automation, which combines online data entry and automated data capture using input devices such as RFID tags or magnetic data strips.  Source data automation is fast and accurate, and minimizes human involvement in the translation process.
  40. 40. Many large companies use a combination of source data automation and a powerful communication network to manage global operations instantly. Some common examples of source data automation are:  Businesses that use point-of-sale (POS) terminals equipped with bar code scanners and magnetic swipe scanners to input credit card data.  Automatic teller machines (ATMs) that read data strips on bank cards.  Factory employees who use magnetic ID cards to clock on and off specific jobs so the company can track production costs accurately.  Hospitals that imprint bar codes on patient identification bracelets and use portable scanners when gathering data on patient treatment and medication.  Retail stores that use portable bar code scanners to log new shipments and update inventory data.  Libraries that use handheld scanners to read optical strips on books.
  41. 41. Tradeoffs  Although online input offers many advantages, it does have some disadvantages.  For example, unless source data automation is used, manual data entry is slower and more expensive than batch input because it is performed at the time the transaction occurs and often done when computer demand is at its highest.  The decision to use batch or online input depends on business requirements. For example, hotel reservations must be entered and processed immediately, but hotels can enter their monthly performance figures in a batch.  In fact, some input occurs naturally in batches. A cable TV provider, for example, receives customer payments in batches when the mail arrives.
  42. 42. Input Volume Reduction The following guidelines will help reduce input volume: 1. Input necessary data only. 2. Do not input data that the user can retrieve from system files or calculate from other data. 3. Do not input constant data. 4. Use codes.
  43. 43. Output Security and Control  Output must be accurate, complete, current, and secure.  Companies use various output control methods to maintain output integrity and security.  Output security protects privacy rights and shields the organization’s proprietary data from theft or unauthorized access.  A diskless workstation is a network terminal that supports a full-featured user interface, but limits the printing or copying of data, except to certain network resources that can be monitored and controlled.
  44. 44. Input Security and Control  Input control includes the necessary measures to ensure that input data is correct, complete, and secure.  Every piece of information should be traceable back to the input data that produced it. That means that you must provide an audit trail that records the source of each data item and when it entered the system.  Data security policies and procedures protect data from loss or damage, which is a vital goal in every organization.  Sensitive data can be encrypted, or coded, in a process called encryption, so only users with decoding software can read it.