ARCHITRACKEvaluating architectural

preferencesvia eyetracker

Keul, A.G.¹ ³, Hutzler, F.²,Frauscher, G.¹ & Voigt, A.³

¹Salzburg University, ²Free University Berlin,

³Vienna University of Technology

ARCHITRACKTypical E&B research on verbal descriptions

of space – where are the behavioral data ? Pilot study & diploma thesis on architectural

perception using eyetracker technology, triangulation of verbal and eyetracker data

Project goal: What can behavioral data on eye movements contribute to the understanding of visual exploration of architectural stimuli?

Earlier papers: Janssens 1984, Lengyel 1988, Kei et al. 2000; IAPS 2004 – Weber paper.

Eye movements & measurements

• Automatic, unconscious eye movements – accomodation, pupil reflex, convergence, nystagms (saccades, pursuit), fixations

• Fixation means input and processing of visual information – interest-based preference

• Measurement techniques – electrooculography, coil, electromyography, infrared reflection oculography (eyetracker)

• Eyetracker widely used in clinical, reading, traffic safety, advertising, software research

Experimental design Salzburg

• Targets: 6 Global Architecture (GA) images (above; housing US/CAN; 3 outdoor, 3 indoor), 10 city/rural (CR) images, wall-projection on silver screen via beamer

• Subjects: 15 persons – 5 male architects and 10 laypeople (5 women, 5 men)

• ISCAN RK-726PCI 50 Hz infrared reflection eyetracker with head-rest

Experimental design

Beamer

Eyetracker

Subject

Experimental run • Briefing, no special instruction, „just look“• 6 GA images set A test round*• 10 CR images set B test round* * 10 sec projection time; sequence

variation; eyetracking every 20 msec; calibration in-between targets

• 6 GA images set A verbal description round

• Debriefing, comments

Fixation protocol samples

Eye movement film sample

Eye movement analysis• Number of fixations (count)• Fixation locations (thematic areas) • F. durations (msec; singular, cumulative)• F. succession (first eye contact,

sequential/repetitive contacts)• Group differences (architects/lay people,

gender)• Triangulation – eyetracker vs. verbal data (here:

thematic word count)• Large differences between stimuli and

subjects – every picture actually a single case study

Experimental resultsMeans, image 1 GA architects, lay male, femalefixations fixation duration duration per fixation 23.5 6116 msec 257.7 msec 19.2 5050 msec 276.9 msec 23.5 4101 msec 172.8 msecfix.archit.-landsc.-furnit. dur.archit.-landsc.-furnit. 13 6.4 1 3168 1908 200 5.6 3 4.4 2000 584 1320 9 2.8 2.8 1760 484 504

Experimental resultsGroup differences - professional focus

hypothesis(architects show more building fixations) not

conclusive – only 4 significant Mann-Whitney differences for 31 thematic areas of the 5 GA pictures. Tendency for experts to prefer facade, for laypeople to visually prefer furnitures.

Gender differences – not true for fixations, no significant general effect.

Succession analysis image GA 1 & 5: No group differences experts – laypeople. Same general pattern of repetitive contacts and fixation series.

Triangulation example 1Sums image 1 GA architectsImage area wordsfixations total dur. (msec)architecture 116 114 15840tree 38 3 400landscape 36 32 9540terrace 5 1 300furniture 6 5 1000sky 0 0 3500Sums image 1 GA laypeople femaleImage area wordsfixations total dur. (msec)architecture 88 45 8800tree 30 7 780landscape 53 14 2420terrace 0 4 420furniture 11 14 2520sky 20 35 5580

Triangulation example 2Sums image 5 GA architectsImage area words fixations total dur.

(msec)gallery 112 22 4540walls 0 23 5200window 10 22 5750furniture 23 39 10100floor 0 4 940Sums image 5 GA laypeople femaleImage area words fixations total dur.

(msec)gallery 42 25 4660walls 0 23 3980window 19 15 3020furniture 13 28 4860floor 0 19 4300

Experimental results

Triangulation: Thematic fixations, their duration and word counts were consistent for picture 1, but inconsistent for picture 5 (above) – visual-verbal gap. No group effects (experts, gender).

Experimental results

PART 2 – Ten city/rural (CR) images (A.Voigt) containing urban gestalt factors of F.Moser. „Gate“ and „vegetation“ images shown above.

Testing UGF for attraction (is it a visual focus?)True for „gate“, „vegetation“, „vanishing

line/point“ – mean percentages of fixations in images :

„gate“ experts 50.8% lay (m) 35.6%„vegetation“ experts 28.6% lay (m) 38.4%

Experimental results

Possibility to test for visual distraction:„Building corner“ (C) of left upper image

consumed 14.8% expert and 24.2% lay (m) fixation time. With distraction (upper right), C only took 5.8%/12.4%, whereas the persons drew 18.2%/16.4% of the attention time.

C C

Conclusions• Eyetracking produces behavioral, objective

data, attractive to planners who show high expectations, but tracker is no easy „test“.

• Simple hypotheses (expert, gender focus) not confirmed – first explorative behavior seems to be similar for different onlookers.

• Eyetracking demonstrates gaps between visual attraction and verbal behavior (as is known from advertising research).

• Eyetracker is a good means to test for a planned attention focus – does it work?

ReferencesDuchowski, A.T. (2003). Eye tracking methodology. London:

Springer.Frauscher, G. (2003). Architekturwahrnehmung und

–beschreibung. Diplomarbeit, Universität Salzburg.Janssens, J. (1984). The effect of professional education and

experience on the perception of building exteriors. IAPS 8, West-Berlin (Germany), 25-29 July.

Kei, A., Akagi, T., Oku, T. & Kusaka, M. (2000). How persons with dementia and developmental disability can avoid barriers on their way? IAPS 16, Paris (France), 4-7 July.

Lengyel, S. (1988). Do we only see what we already know? IAPS 10, Delft (Netherlands), 5-8 July.

Moser, F., Frei, W.D. & Voigt, A. (1988). Wohnbau im Ortsbild. Wien: Picus.

Rayner, K. (1998). Eye movements in reading and information processing: 20 years of information. Psychological Bulletin, 124, 372-422.

Weber, R. (2004). Applications of simulation procedures to experimental aesthetics and to design decisions in architecture. IAPS 18, Vienna (Austria), 7-9 July.

ContactDr.Alexander G. Keul, Associate Professor,

Psychology Department, Salzburg University, Hellbrunnerstr.34, A-5020 Salzburg, Austria, Europe

Phone+fax 0043 (0)662 8044 5127E-Mail alexander.keul@sbg.ac.athttp://www.sbg.ac.at/psy/people/keul.htm

Thank you for your interest!