1 what is usable is usable master thesis presentation marijn kampf 26 august 2004 15:15 – 16:15
TRANSCRIPT
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What is usable is usable
Master Thesis Presentation
Marijn Kampf
26 august 200415:15 – 16:15
Master Thesis Presentation
2 / 19
Marijn Kampf
Agenda
• Introduction• Critique of Tractinsky• Experiment I• Experiment II• Discussion & Conclusions• Questions
Master Thesis Presentation
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Marijn Kampf
Introduction
• Relations between aesthetics and usability
• Aesthetics and “traditional” Human-Computer Interaction (HCI)
• Critique on Tractinsky
Master Thesis Presentation
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Previous research
• Kurosu and Kashimura (1995)- Apparent vs. inherent usability- Introduced ATM displays
• Tractinsky (1997)- Replication in different cultural settings
• Tractinsky (2000)- Added functionality- Aesthetics affected post-use
perceptions of aesthetics and usability. Actual usability did not.
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Tractinsky’s experiment (2000)
• Aesthetic and usability manipulation
• 3 stages- Pre test stage
- 9 interfaces pre experiment rating - Test stage
- Assigned to aesthetic level- Participants practice with ATM- Assigned to usability level- Participants perform ATM tasks
- Post test stage- Post experiment rating
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Critique on Tractinsky
• Influence participants by showing all interfaces• Pre and post question consistency• Questionnaire• Usability manipulation
- Delay in processing time
- Buttons not always operating
- Shortcut unavailable
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Research questions
• H1: Post-experimental measures will not indicate strong correlations between perceived aesthetics and perceived usability if the participants see only one screen design
• H2: A better actual usability will correspond to a better perceived usability
• Using a more elaborate measure of aesthetics and perceived usability
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Method
• 83 participants• 2 x 2 groups design
- Aesthetics- Usability
• Procedure- Randomly assigned to one of four conditions- Pre-test questionnaire- Practice tasks / Actual tasks- Post-test questionnaire
High aesthetics Low aesthetics
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Results
• Actual usability variable• Manipulation check
- Two-way ANOVA’s effect on completion times- Usability factor (F1,78 = 236.975; p < 0.001)
- Aesthetics interface (F1,78 = 6.725; p = 0.011)
• Regression analysis perceived post-usability: - 51.8% variance (R2
adj = 49.9%; F3, 78 = 27.9; p < .001)
- Post-classic aesthetics (t78 = 6.471; beta = .529; p < .001)
- Perceived pre-usability (t78 = 3.522; beta = .288; p = .001)
- Task times (t78 = -3.271; beta = -.257; p = .002)
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Discussion
• H1: Post-experimental measures will not indicate strong correlations between perceived aesthetics and perceived usability if the participants see only one screen design
• H2: A better actual usability will correspond to a better perceived usability
• Using a more elaborate measure of aesthetics and perceived usability
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Marijn Kampf
Conclusions
• Actual usability does have an effect on perceived usability with our usability manipulation
• Judged aesthetics had an effect on perceived usability• The aesthetics effect on perceived usability may have
been due to the effect on actual usability
Judged Aesthetics
Perceived Usability
Actual Usability
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Experiment II
• H1: Aesthetics do not influence the perceived usability if aesthetics do not influence actual usability
• Create designs which differ on classic and expressive aesthesis dimensions
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Differences first experiment
• Procedure- Additional questions
• Scales• Method
- 83 participants (26 downloadable version)
• Design- 2 x 2 between groups- Classic aesthetics- Expressive aesthetics
High Low
Hig
hE
xpre
ssiv
e ae
sthe
tics
Lo
w
Classic aesthetics
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Results
Manipulation check
- No effect on average completion times of interface conditions
- Manipulated classic aesthetics
- Failed to manipulate expressive aesthetics• Found effect of expressive aesthetics on perceived
post-usability, not from classic aesthetics.
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Marijn Kampf
Results
Regression analysis• Influence on perceived post-usability
Variance explained: 61.3%; R2adj = 58.8%; F5, 77 = 24.407; p < .001
- Pre-perceived usability (t77 = 5.710; beta = .437; p < .001)
- Post-classic aesthetics (t77 = 5.402; beta = .480; p < .001)
- Pre-expressive aesthetics (t77 = -4.000; beta = -.439; p < .001)
- Expressive aesthetics factor (t77 = -3.012; beta = -.225; p = .004)
- Post-expressive aesthetics (t77 = 2.316; beta = .270; p = .023)
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Discussion
• H1: Aesthetics do not influence the perceived usability if aesthetics do not influence actual usability
• Create designs which differ on classic and expressive aesthesis dimensions
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General discussion & conclusions
Discussion• Limited experiment
- Can an ATM be aesthetic?• Results 1st experiment contradict Tractinsky
- Usability manipulation might explain differences• Functional and “box” aesthetics
- Functional: Form follows function• What is usable is usable
Conclusion• Aesthetics could influence both actual and perceived usability
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Questions
• Are there questions or comments?
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References
• [BANHAM_1972] Reyner Banham; Theory and design in the first machine age; 1972; Pages 320-321• [KUROSU_1995] Masaaki Kurosu and Kaori Kashimura; Apparent Usability vs. Inherent Usability
Experimental analysis on the determinants of the apparent usability; Association for Computing Machinery; CHI 95 - Conference on Human Factors in Computing Systems; 1995
• [LAVIE_2004] Talia Lavie and Noam Tractinsky; Assessing dimensions of perceived visual aesthetics of web sites*1; International Journal of Human-Computer Studies; Volume 60; Issue 3; March 2004; Pages 269-298
• [LINDGAARD_2003] Gitte Lindgaard and Cathy Dudek; What is this evasive beast we call user satisfaction?; Interacting with Computers; Volume 15; Issue 3; June 2003; Pages 429-445
• [NIELSEN_1993] Jakob Nielsen; Usability Engineering; Morgan Kaufmann; 1993;• [NORMAN_2002] Don A. Norman; Emotion and design: Atrractive things work better; Interactions
Magazine; Volume 4; July/August 2002; Pages 36-42; http://www.jnd.org/dn.mss/Emotion-and-design.html• [NORMAN_2003] Don A. Norman; Emotional Design: Why We Love (Or Hate) Everyday Things; Basic
Books; 23-Dec-03; Chapter 1; http://www.jnd.org/ED_Draft/CH01.pdf• [PARK_2004] Su-e Park, Dongsung Choi and Jinwoo Kim; Critical factors for the aesthetic fidelity of web
pages: empirical studies with professional web designers and users; Interacting with Computers; Volume 16; Issue 2; April 2004; Pages 351-376
• [SCHAIK_2004] Paul van Schaik and Jonathan Ling; The effects of screen ratio and order on information retrieval in web pages; Displays; In Press, Corrected Proof; Available online 10 February 2004;
• [SNIJDERS_2003] Tom A.B. Snijders; Multilevel Analysis in M. Lewis-Beck, A.E. Bryman, and T.F. Liao (eds.); The SAGE Encyclopedia of Social Science Research Methods; Volume 2; 2003; Pages 673-677; http://stat.gamma.rug.nl/snijders/MultilevelAnalysis.pdf
• [TRACTINSKY_1997] Noam Tractinsky; Aesthetics and Apparent Usability: Empirically Assessing Cultural and Methodological Issues; Association for Computing Machinery; CHI 97 - Conference on Human Factors in Computing Systems; 1997;
• [TRACTINSKY_2000] N. Tractinsky, A. S. Katz and D. Ikar; What is beautiful is usable; Interacting with Computers; Volume 13; Issue 2; December 2000; Pages 127-145