CHI: evaluatie

#chikul13Leuven, 19 February 2012

Erik Duvalhttp://erikduval.wordpress.com

@ErikDuval

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http://www.slideshare.net/erik.duval

Criteria for evaluation:what do you think?

• ... • ...

criteria

•Usability

•Usefulness

•Meaning

•(aesthetic) Qualities

•Sociability

•Learnability

•Efficiency

•Memorability

•Accuracy

•Satisfaction

[Nielsen, 1993]

• formatief

• tijdens het ontwikkelen

•om te verbeteren

•summatief

•op het einde

•om te bewijzen dat “het (niet) werkt”

http://semanticstudios.com/publications/semantics/000029.php

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

methods

- questionnaire- usability engineering- by experts- usage tracking

questionnaires

http://hcibib.org/perlman/question.html

Usability LabFhttp://www.cc.gatech.edu/gvu/images/lab/usability-lab.jpg

Usability engineering

•‘Think-aloud protocol‘

•Video recording with annotation

•Log, remarks, etc. for analysis

•‘Discount usability engineering’

•Comparative test of user interface

By experts

•in HCI or domain

•very effective

•delicate relation with developers

•target

•identify problems

•suggest solutions

•through checklist of guidelines

User tracking

•“attention metadata”

•google analytics

Participants

• representative

• computer experience, language, task, motivation, education, etc.

• gender, age

• have to know they are not being evaluated

• relationship

• colleagues, friends, family, ...

they are ... human beings

how many?

Text

http://www.useit.com/alertbox/20000319.html

http://www.useit.com/alertbox/20000319.html

•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

Factors that influence usability:what do you think?

•... •...

Factoren: Cognitief

•cognitive•fatigue, boredom, stress, fear, ...•personality•gender (‘abort’)•cultural•i18n

Trash can in Thailand

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http://erikduval.wordpress.com/@ErikDuval