Abstract
In the course of running an eye-tracking experiment, one computer system or subsystem typically presents the stimuli to the participant and records manual responses, and another collects the eye movement data, with little interaction between the two during the course of the experiment. This article demonstrates how the two systems can interact with each other to facilitate a richer set of experimental designs and applications and to produce more accurate eye tracking data. In an eye-tracking study, a participant is periodically instructed to look at specific screen locations, orexplicit required fixation locations (RFLs), in order to calibrate the eye tracker to the participant. The design of an experimental procedure will also often produce a number ofimplicit RFLs—screen locations that the participant must look at within a certain window of time or at a certain moment in order to successfully and correctly accomplish a task, but without explicit instructions to fixate those locations. In these windows of time or at these moments, the disparity between the fixations recorded by the eye tracker and the screen locations corresponding to implicit RFLs can be examined, and the results of the comparison can be used for a variety of purposes. This article shows how the disparity can be used to monitor the deterioration in the accuracy of the eye tracker calibration and to automatically invoke a re-calibration procedure when necessary. This article also demonstrates how the disparity will vary across screen regions and participants and how each participant’s uniqueerror signature can be used to reduce the systematic error in the eye movement data collected for that participant.
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Aaltonen, A., Hyrskykari, A., &Räihä, K.-J. (1998). 101 spots, or how do users read menus? InProceedings of CHI 98 (pp. 132–139). New York: ACM Press.
Abrams, R. A., &Jonides, J. (1988). Programming saccadic eye movements.Journal of Experimental Psychology: Human Perception & Performance,14, 428–443.
Abrams, R. A., Meyer, D. E., &Kornblum, S. (1989). Speed and accuracy of saccadic eye movements: Characteristics of impulse variability in the oculomotor system.Journal of Experimental Psychology: Human Perception & Performance,15, 529–543.
Abrams, R. A., Meyer, D. E., &Kornblum, S. (1990). Eye-hand coordination: Oculomotor control in rapid aimed limb movements.Journal of Experimental Psychology: Human Perception & Performance,16, 248–267.
Byrne, M. D., Anderson, J. R., Douglass, S., &Matessa, M. (1999). Eye tracking the visual search of click-down menus. InProceedings of CHI 99 (pp. 402–409). New York: ACM Press.
Card, S. K., Pirolli, P., Wege, M.V.D., Morrison, J.B., Reeder, R. W., Schraedley, P. K., &Boshart, J. (2001). Information scent as a driver of Web behavior graphs: Results of a protocol analysis method for Web usability. InProceedings of CHI 2001 (pp. 498–505). New York: ACM Press.
Chapanis, A., Garner, W. R., &Morgan, C. T. (1949).Applied experimental psychology: Human factors in engineering design. New York: Wiley.
Findlay, J. M., Brogan, D., &Wenban-Smith, M. G. (1993). The spatial signal for saccadic eye movements emphasizes visual boundaries.Perception & Psychophysics,53, 633–641.
Findlay, J. M., &Gilchrist, I. D. (1998). Eye guidance and visual search. In G. Underwood (Ed.),Eye guidance in reading and scene perception (pp. 295–312). Amsterdam: Elsevier.
Halverson, T., & Hornof, A. J. (2001).Issues in the design and development of experimental software for use with an eye tracking system (Tech. Rep. 02-02). Eugene: University of Oregon, Department of Computer and Information Science. Available at ftp://ftp.cs.uoregon.edu/pub/hornof/EyeGazeMac.pdf.
Helsen, W. F., Elliott, D., Starkes, J. L., &Ricker, K. L. (1998). Temporal and spatial coupling of point of gaze and hand movement in aiming.Journal of Motor Behavior,30, 249–259.
Hornof, A. J. (2001). Visual search and mouse pointing in labeled versus unlabeled two-dimensional visual hierarchies.ACM Transactions on Computer-Human Interaction,8, 171–197.
Lankford, C. (2000). Gazetracker™: Software designed to facilitate eye movement analysis. InProceedings of the Eye Tracking Research and Applications Symposium (pp. 51–55). New York: ACM Press.
LCTechnologies. (2001).The Eyegaze Development System: A tool for eyetracking applications. Fairfax, VA: Author.
Pirolli, P., Card, S. K., &Van Der Wege, M. M. (2001). Visual information foraging in a focus + context visualization. InProceedings of CHI 2001 (pp. 490–497). New York: ACM Press.
Pollatsek, A., Rayner, K., &Henderson, J. M. (1990). Role of spatial location in integration of pictorial information across saccades.Journal of Experimental Psychology: Human Perception & Performance,16, 199–210.
Posner, M. I. (1980). Orienting of attention.Quarterly Journal of Experimental Psychology,32, 3–25.
Rosenbaum, D. A. (1991).Humanmotor control. New York: Academic Press.
Salvucci, D. D. (2000). An interactive model-based environment for eye-movement protocol analysis and visualization. InProceedings of the Eye Tracking Research and Applications Symposium, (pp. 57–63). New York: ACM Press.
Salvucci, D. D., &Anderson, J. R. (2001). Automated eye-movement protocol analysis.Human-Computer Interaction,16, 39–86.
Salvucci, D. D., &Goldberg, J. H. (2000). Identifying fixations and saccades in eye-tracking protocol. InProceedings of the Eye Tracking Research and Applications Symposium (pp. 71–78). New York: ACM Press.
Smith, B. A., Ho, J., Ark, W., &Zhai, S. (2000). Hand-eye coordination patterns in target selection. InProceedings of the Eye Tracking Research and Applications Symposium (pp. 117–122). New York: ACM Press.
Wickens, C. D. (1984).Engineering psychology and human performance. Columbus, OH: Merrill.
Woodworth, R. S. (1899). The accuracy of voluntary movement.Psychological Review,3 (Monograph Suppl. No. 2).
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This work was supported by the Office of Naval Research through Grant N00014-01-10548 to the University of Oregon, Anthony J. Hornof, principal investigator.
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Hornof, A.J., Halverson, T. Cleaning up systematic error in eye-tracking data by using required fixation locations. Behavior Research Methods, Instruments, & Computers 34, 592–604 (2002). https://doi.org/10.3758/BF03195487
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DOI: https://doi.org/10.3758/BF03195487