HCI: evaluation

HCI: evaluatie KU Leuven, B, 17 February 2014 !

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

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

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Criteria for evaluation: what do you think?

criteria

•Usability

•Usefulness

•Meaning

• (aesthetic) Qualities

•Sociability

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

Usability

• Learnability: time to learn the application • Efficiency: time to perform task • Memorability: timethat users remember how and what • Accuracy: number and kind of errors • satisfaction: subjective feeling

Often a compromise - important to make explicit

• formatief

• tijdens het ontwikkelen

•om te verbeteren

•summatief

•op het einde

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

methods !

- questionnaire - usability engineering - by experts - usage tracking

questionnaires

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

Usability Labhttp://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

@ErikDuval http://erikduval.wordpress.com

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