11. Criteria
• Time
• to learn the application
• to perform task
12. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
13. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
• Errors
14. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
• Errors
• number
15. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
• Errors
• number
• kind
16. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
• Errors
• number
• kind
• Subjective feeling of satisfaction
17. Criteria
• Time
• to learn the application
• to perform task
• that users remember how and what
• Errors
• number
• kind
• Subjective feeling of satisfaction
Often a compromise - important to make explicit
21. Usability engineering
•‘Think-aloud protocol‘
•Video recording with annotation
•Log, remarks, etc. for analysis
•‘Discount usability engineering’
•Comparative test of user interface
31. Participants
• representative
• computer experience, language, task,
motivation, education, etc.
• gender, age
• have to know they are not being evaluated
• relationship
• colleagues, friends, family, ...
34. how many?
Text
http://www.useit.com/alertbox/20000319.html
http://www.useit.com/alertbox/20000319.html
35. • every test user finds fraction L of usability
issues
• independent test users
n users find fraction 1-(1-L)n
• L=31% 85% for n=5, 99% for n=15
L=8% 35% for n=5
