7. 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
11. Usability engineering
•‘Think-aloud protocol‘
•Video recording with annotation
•Log, remarks, etc. for analysis
•‘Discount usability engineering’
•Comparative test of user interface
12. By experts
•in HCI or domain
•very effective
•delicate relation with developers
•target
•identify problems
•suggest solutions
•through checklist of guidelines
14. Participants
• representative
• computer experience, language, task,
motivation, education, etc.
• gender, age
• have to know they are not being evaluated
• relationship
• colleagues, friends, family, ...
17. how many?
Text
http://www.useit.com/alertbox/20000319.html
http://www.useit.com/alertbox/20000319.html
18. • 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
