Heuristic evaluation aka Usability Inspection

1. Heuristic evaluation aka Usability Inspection and guidelines

2. Heuristic evaluation Developed Jacob Nielsen in the early 1990s. Based on heuristics distilled from an empirical analysis of 249 usability problems. These heuristics have been revised for current technology. Heuristics being developed for mobile devices, wearables, virtual worlds, etc. Design guidelines form a basis for developing heuristics. 2

3. Nielsen’s original heuristics Visibility of system status. Match between system and real world. User control and freedom. Consistency and standards. Error prevention. Recognition rather than recall. Flexibility and efficiency of use. Aesthetic and minimalist design. Help users recognize, diagnose, recover from errors. Help and documentation. http://www.nngroup.com/articles/ten-usability-heuristics/ 3

4. Visibility of system status The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.   • Match between system and the real world The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.   • User control and freedom Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.   • Consistency and standards Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.   • Error prevention Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.  

5. Recognition rather than recall Minimize the user's memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.   • Flexibility and efficiency of use Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.   • Aesthetic and minimalist design Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.   • Help users recognize, diagnose, and recover from errors Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.   • Help and documentation Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

6. Activity: Identify potential trade-offs Visibility of system status. Match between system and real world. User control and freedom. Consistency and standards. Error prevention. Recognition rather than recall. Flexibility and efficiency of use. Aesthetic and minimalist design. Help users recognize, diagnose, recover from errors. Help and documentation. 6

7. What does this graph tell you? Shows which evaluators found which usability problems in HEof a banking system. Each row is an evaluator (n=19) and each column is a flaw (n=16) Black squares show where evaluator found the problem. The rows are sorted with most successful evaluators at the bottom. The columns are sorted with easiest to find problems at right. http://www.nngroup.com/articles/how-to-conduct-a-heuristic-evaluation/

8. Discount evaluation Heuristic evaluation is referred to as discount evaluation when 5 evaluators are used. Empirical evidence suggests that on average 5 evaluators identify 75-80% of usability problems. 8

9. No. of evaluators & problems 9

10. Main stages of heuristic evaluation Preliminaries Agreed set of heuristics to use; Programming team member overviews system; And team member is available throughout; Set of tasks; Evaluation: Each expert works independently through the UI; Team member records problems, so expert can simply state them (single person works well, so they bring all details together); Also answers any questions (eg expert gets stuck, cannot find how to do a task, may need help with domain expertise aspects) Multiple passes (overview, then detailed) Results in a set of identified failures to match the heuristics (part of interface, violated heuristic) Concluding summary Summarise all the flaws Rate these in terms of severity 10

11. Critical to success • Set of heurstics • Set of tasks • Prototype interface • Experts!!!

12. Advantages and problems Few ethical & practical issues to consider because users not involved. Can be difficult & expensive to find experts. Best experts have knowledge of application domain & users. Best if experts are not the designers.T Biggest problems: Important problems may get missed; Many trivial problems are often identified; Experts have biases; May encourage tinkering with the interface detailed in the identified problems. 12

13. About heuristics There are many options The link between design and evaluation

14. Goals of INFO3315 Learn about the range of techniques to: Understand users Establish requirements Brainstorm alternatives creatively Prototyping alternative Evaluate these Reflect on strengths and weaknesses of prototypes Learn how to actually use a core set of these techniques

15. High level heuristics Harder for novices to use effectively

16. Nielsen’s original heuristics Visibility of system status. Match between system and real world. User control and freedom. Consistency and standards. Error prevention. Recognition rather than recall. Flexibility and efficiency of use. Aesthetic and minimalist design. Help users recognize, diagnose, recover from errors. Help and documentation. http://www.nngroup.com/articles/ten-usability-heuristics/ 16

17. Ben Shneiderman's golden rules for dialogue • Consistency • eg location of “quit” • short cuts for frequent users • informative feedback • HTTP Error 404 !!! • closure in dialogues • (ie clear when action is complete) • simple error handling • easy reversal of actions • undo • support internal locus of control • Users should feel in control • reduce short term memory load

18. Bruce Togazzini • http://www.asktog.com/basics/firstPrinciples.html • Anticipation • Autonomy • Color Blindness • Consistency • Defaults • Efficiency of the User • Explorable Interfaces • Fitts' Law • Human Interface Objects • Latency Reduction • Learnability • Metaphors, Use of • Protect Users' Work • Readability • Track State • Visible Navigation

19. Many other guidelines • Company specific • Device/OS specific • eghttps://developer.apple.com/library/mac/documentation/userexperience/conceptual/applehiguidelines/Windows/Windows.html • ISO, ANSI Standards • National Standards • Military Standards • Accessibility Standards

20. More specialised heuristics Narrower than all interaction (eg door opener)

21. Heuristics for websites focus on key criteria (Budd, 2007) Clarity Minimize unnecessary complexity & cognitive load Provide users with context Promote positive & pleasurable user experience 21

22. OS X Example • “mental model your users have should infuse the design … support the user’s mental model by striving to incorporate the following characteristics • Familiarity • Simplicity • Availability (functionality available) • Discoverability • https://developer.apple.com/library/mac/documentation/userexperience/conceptual/applehiguidelines/Intro/Intro.html#//apple_ref/doc/uid/TP30000894-TP6 (visited 2013)

23. Drill down • Class activity on heuristic calling for Simplicity • What were things you discovered in your Think-Aloud usability evaluations where you discovered that you had failed to do this.

24. Fine-grained guidelines Easier for less experienced evaluators

25. Text guidelines • Avoid negatives (sic) • Short simple sentences. • Active voice (not passive). • AVOID UPPER CASE • Note: CW Q2 relates to these

26. Tabletop heuristics • General heuristics • Shneiderman (1992) Nielsen (1994) • Groupware • Baker et al. (2002) • Large screen Information Exhibits • Somervell et al. (2003) Czerwinski et al. (2006) T. Apted,A. Collins, and J. Kay. Heuristics to support design of new software for interaction at tabletops. In CHI ’09 Workshop on Multitouch and Surface Computing, 2009.

27. 1. Design independently of table size (e.g. easily resize interface elements) 2. Support reorientation (support users working at any table position) 3. Consider human reach (avoid unreachable, fixed interface elements) 4. Use large selection points (support large input cursors/fingers) 5. Manage interface clutter (quick removal/hiding of information; consider multiple users) 6. Use table space efficiently (avoid modal behaviour, support private/group spaces) 7. Support private/group interaction (usable as a private or shared resource)

28. How would one validate a set of heuristics? And how would you know about this?

29. How to select appropriate heuristics? Context Validity Usability (broad versus detailed)

30. Summary of HE • No users needed • Heuristics needed • Experts needed (NOT the designers…) • Relatively cheap