Dario D. Salvucci
Joseph H. Goldberg
ABSTRACT
The process of fixation identification—separating and labeling fixations and saccades in eye-tracking protocols—is an essential part of eye-movement data analysis and can have a dramatic impact on higher-level analyses. However, algorithms for performing fixation identification are often described informally and rarely compared in a meaningful way. In this paper we propose a taxonomy of fixation identification algorithms that classifies algorithms in terms of how they utilize spatial and temporal information in eye-tracking protocols. Using this taxonomy, we describe five algorithms that are representative of different classes in the taxonomy and are based on commonly employed techniques. We then evaluate and compare these algorithms with respect to a number of qualitative characteristics. The results of these comparisons offer interesting implications for the use of the various algorithms in future work.
- 1.Alpern, M. (1962). Type of movement. In H. Davson (Ed.), The Eye, Vol. 3. (pp, 63-151). New York: Academic Press.Google Scholar
- 2.Camerini, P. M., 13albiati, 13, & Maffioli, F. (1988). Algorithms for finding optimum trees: Description, use and evaluation. Annals of Operations Research, 13, 265- 397.Google ScholarCross Ref
- 3.DenBuurman, R., Boersma, T., & Gerrisen, J. F. (1981). Eye movements and the perceptual span in reading. Reading Research Quarterly, 16, 227-235.Google ScholarCross Ref
- 4.Ditchburn, R. W. (1980). The function of small saccades. Vision Research, 20, 271-272.Google ScholarCross Ref
- 5.Erkelens, C. J., & Vogels, I. M. L. C. (1995). The initial direction and landing position of saccades. In J. M. Findiay, R. Walker, & R. W. Kentridge (Eds.), Eye Movement Research: Mechanisms, Processes, and Applications (pp. 133-144). New York: Elsevier.Google Scholar
- 6.Fuchs, A. F. (1971). The saccadic system. In P. Bach-y- Rita, C. C. Collins, & J. E. Hyde (Eds.), The Control of Eye Movements (pp. 343-362). New York: Academic Press.Google Scholar
- 7.Goldberg, J. H,, & Schryver, J. C. (1995). Eye-gazecontingent control of the computer interface: Methodology and example for zoom detection. Behavior Research Methods, Instruments, & Computers, 27, 338- 350.Google Scholar
- 8.Hartigan, J. A. (1975). Clustering algorithms. New York: John Wiley & Sons. Google ScholarDigital Library
- 9.Just, M. A., & Carpenter, P. A. (1984). Using eye fixations to study reading comprehension. In D. E. Kieras & M. A. Just (Eds.), New Methods in Reading Comprehension Research (pp. 151-182). Hillsdale, NJ: Erlbaum.Google Scholar
- 10.Karsh, R., & Breitenbach, F. W. (1983). Looking at looking: The amorphous fixation measure. In R, Groner, C. Menz, D. F. Fisher, & R. A. Monty (Eds.), Eye Movements and Psychological Functions: International Views (pp. 53-64). Hillsdale, NJ: Erlbaum.Google Scholar
- 11.Land, M. F., & Lee, D. N. (1994). Where we look when we steer. Nature, 369, 742-744.Google ScholarCross Ref
- 12.Noton, D., & Stark, L. (1971). Scanpaths in saccadic eye movements while viewing and recognizing patterns. Vision Research, 11, 929-942.Google ScholarCross Ref
- 13.Rabiner, L. R. (1989). A tutorial on hidden Markov models and selected applications in speech recognition. Proceedings of the IEEE, 77, 257-286.Google ScholarCross Ref
- 14.Rayner, K. (1995). Eye movements and cognitive processes in reading, visual search, and scene perception. In J. M. Findlay, R. Walker, & R. W. Kentridge (Eds.), Eye Movement Research: Mechanisms, Processes, and Applications (pp. 3-21). New York: Elsevier.Google Scholar
- 15.Salvucci, D. D. (1999). Mapping eye movements to cognitive processes. Doctoral Dissertation, Department of Computer Science, Carnegie Mellon University. Google ScholarDigital Library
- 16.Salvucci, D. D., & Anderson, J. R. (1998). Tracing eye movement protocols with cognitive process models. In Proceedings of the Twentieth Annual Conference of the Cognitive Science Society (pp. 923-928). Hillsdale, NJ: Erlbaum.Google Scholar
- 17.Salvucci, D. D., & Anderson, J. R. (in press). Integrating analogical mapping and general problem solving: The path-mapping theory. Cognitive Science.Google Scholar
- 18.Sen, T., & Megaw, T. (1984). The effects of task variables and prolonged performance on saccadie eye movement parameters. In A. G. Gale & F. Johnson (Eds.), Theoretical and Applied Aspects of Eye Movement Research (pp. 103-111). Amsterdam: Elsevier.Google Scholar
- 19.Stark, L., & Ellis, S. R. (1981). Scanpath revisited: Cognitive models of direct active looking. In D. F. Fisher, R. A. Monty, & J. W. Senders (Eds.), Eye Movements: Cognition and Visual Perception (pp. 193- 226). Hillsdale, NJ: Erlbaum.Google Scholar
- 20.Suppes, P. (1990). Eye-movement models for arithmetic and reading performance. In E. Kowler (Ed.), Eye Movements and their Role in Visual and Cognitive Processes (pp. 455-477). New York: Elsevier.Google Scholar
- 21.Widdel, H. (1984). Operational problems in analysing eye movements. In A. 13. Gale & F. Johnson (Eds.), Theoretical and Applied Aspects of Eye Movement Research (pp. 21-29). New York: Elsevier.Google Scholar
Index Terms
- Identifying fixations and saccades in eye-tracking protocols
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