1 What is usable is usable Master Thesis Presentation Marijn Kampf 26 august 2004 15:15 – 16:15.

1

What is usable is usable

Master Thesis Presentation

Marijn Kampf

26 august 200415:15 – 16:15


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Agenda

• Introduction• Critique of Tractinsky• Experiment I• Experiment II• Discussion & Conclusions• Questions


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Introduction

• Relations between aesthetics and usability

• Aesthetics and “traditional” Human-Computer Interaction (HCI)

• Critique on Tractinsky


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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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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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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

1 What is usable is usable Master Thesis Presentation Marijn Kampf 26 august 2004 15:15 – 16:15.

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