1. Multimedia Specification Design and Production 2012 / Semester 1 / week 5 Lecturer: Dr. Nikos Gazepidis gazepidis@ist.edu.gr

2. 2 Outline  Multimedia interfaces and applications.  Usability Nielsen’s Heuristics  Graphical examples Multimedia and HCI

3. 3 Nielsen’s Usability Heuristics Multimedia and HCI Jakob Nielsen's heuristics are probably the most-used usability heuristics for user interface design. Nielsen developed the heuristics based on work together with Rolf Molich in 1990. The final set of heuristics that are still used today were released by Nielsen in 1994. The heuristics as published in Nielsen's book Usability Engineering are as follows. Most usability evaluators use the set of heuristics developed 17 years ago by Rolf Molich and Jakob Nielsen. Before this work, lots of people had derived guidelines and principles for usability but there were often so many guidelines that an expert review could take many days to complete. (For example, Smith and Mosier's Guidelines For Designing User Interface Software has 944 guidelines [1] and remains the largest collection of publicly available user interface guidelines in existence.) [1] http://www.hcibib.org/sam/contents.html

4. 4 Nielsen’s Usability Heuristics Multimedia and HCI 1. Visibility of system status - FEEDBACK The system should always keep users informed about what is going on, through appropriate feedback within reasonable time. 2. Match between system and the real world - METAPHOR The system should speak the user's 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. 3. User control and freedom - NAVIGATION 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. 4. Consistency and standards - CONSISTENCY Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.

5. 5 Nielsen’s Usability Heuristics Multimedia and HCI 5. Error prevention - 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. 6. Recognition rather than recall – MEMORY 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. 7. Flexibility and efficiency of use - EFFICIENCY 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

6. 6 Nielsen’s Usability Heuristics Multimedia and HCI 8. Aesthetic and minimalist design - 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. 9. Help users recognize, diagnose, and recover from errors - RECOVERY Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution. 10. Help and documentation - HELP 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.

7. 7 1. Visibility of system status (FEEDBACK) Multimedia and HCI

8. 8 1. Visibility of system status (FEEDBACK) Multimedia and HCI

9. 9 2. Match between system and the real world (METAPHOR) Multimedia and HCI

10. 10 2. Match between system and the real world (METAPHOR) Multimedia and HCI

11. 11 3. User control & freedom (NAVIGATION) Multimedia and HCI

12. 12 3. User control & freedom (NAVIGATION) Multimedia and HCI

13. 13 4. Consistency & standards (CONSISTENCY) Multimedia and HCI

14. 14 4. Consistency & standards (CONSISTENCY) Multimedia and HCI

15. 15 5. Error prevention (PREVENTION) Multimedia and HCI

16. 16 5. Error prevention (PREVENTION) Multimedia and HCI

17. 17 6. Recognition rather than recall (MEMORY) Multimedia and HCI

18. 18 6. Recognition rather than recall (MEMORY) Multimedia and HCI

19. 19 7. Flexibility and efficiency of use (EFFICIENCY) Multimedia and HCI

20. 20 7. Flexibility and efficiency of use (EFFICIENCY) Multimedia and HCI

21. 21 8. Aesthetic and minimalistic design (DESIGN) Multimedia and HCI

22. 22 8. Aesthetic and minimalistic design (DESIGN) Multimedia and HCI

23. 23 9. Help users recognize, diagnose, and recover from errors (RECOVERY) Multimedia and HCI

24. 24 9. Help users recognize, diagnose, and recover from errors (RECOVERY) Multimedia and HCI

25. 25 10. Help and documentation (HELP) Multimedia and HCI

26. 26 10. Help and documentation (HELP) Multimedia and HCI

27. 27 Website Usability Checklist Multimedia and HCI