Eyetracking tips: Eyetracking tips


Experiment design: Experiment design How many participants do you need? How will you get participants? What will participants tolerate? Will participants need to practice? What other data do you want to record? Take into account margin of error Build-in recalibration breaks


Calibration: Calibration Eyetracker can have problems calibrating: Bi-focal/tri-focal lenses Super-dense lenses Hard contact lenses Lazy eye Large pupils (“crescent effect”) Small pupils Low pupil contrast Random


Piloting: Piloting The experiment presentation needs to be piloted, just like any other interface: Controls Instructions screens Feedback Conclusion screens Timing of trials Length of sessions Use your usability evaluation skills!


Piloting: Piloting


Correcting data: Correcting data Margin of error Accurate to within 0.45 degrees = 12.8 pixels 2 types of error: Absolute drift Relative warp


Correcting data: Correcting data Absolute drift


Correcting data: Correcting data Absolute drift (Corrected)


Correcting data: Correcting data Relative Warp


Filtering data: Filtering data Need to filter data by defining “areas of interest”


Filtering data: Filtering data Areas of interest and buffer zones:


Preparing data for analysis: Preparing data for analysis Understand what format and structure your data needs to be in so you can analyse it: Minimise manual data editing at all costs! Raw data files (corrected)


Useful references: Useful references (Specially recommended titles are highlighted)


Slide14: References Eyetracking Goldberg, H. J., & Kotval, X. P. (1999). Computer interface evaluation using eye movements: methods and constructs. International Journal of Industrial Ergonomics, 24, 631-645. Jacob, R. J. K. (1995). Eye-Tracking in Advanced Interface Design. In: Barfield, W., & Furness, T.A. (Eds.), Virtual Environments and Advanced Interface Design. NY: Oxford University Press. Retrieved May 2003 from http://www.cs.tufts.edu/~jacob/papers/barfield.pdf. Jacob, R. J. K., & Karn, K. S. (2003). Eye Tracking in Human-Computer Interaction and Usability Research: Ready to Deliver the Promises. In Hyönä, J., Radach, R., & Deubel, H. (Eds.).The mind's eye: cognitive and applied aspects of eye movement research. Amsterdam: Elzevier


Slide15: References Eye tracking (cont.) Karn, K., Goldberg, J., McConkie, G., Rojna, W., Salvucci, D., Senders, J., Vertegaal, R., & Wooding, D. (2000). "Saccade Pickers" vs. "Fixation Pickers": The Effect of Eye Tracking Instrumentation on Research. (Panel presentation). Abstract in Proceedings of the Eye Tracking Research and Applications Symposium 2000, p. 87. NY: ACM Press. Marshall, S. (2000). Method and Apparatus for Eye Tracking and Monitoring Pupil Dilation to Evaluate Cognitive Activity. U.S. Patent 6,090,051, July 2000. Poole, A. & Ball, L. J. (in press). Eye Tracking in Human-Computer Interaction and Usability Research: Current Status and Future Prospects. In Ghaoui, Claude (Ed.). Encyclopedia of Human Computer Interaction. Idea Group Available online at http://www.alexpoole.info


Slide16: References Eye tracking (cont.) Poole, A., Ball, L. J., & Phillips, P. (2004). In search of salience: A response time and eye movement analysis of bookmark recognition. In S. Fincher, P. Markopolous, D. Moore, & R. Ruddle (Eds.), People and Computers XVIII-Design for Life: Proceedings of HCI 2004. London: Springer-Verlag Ltd Stampe, D. (1993). Heuristic filtering and reliable calibration methods for video based pupil-tracking systems. Behaviour Research Methods, Instruments, & Computers, 25(2), 137-142.


Slide17: References Eye movements and reading Anderson, R. C., Goldberg, S. R., & Hidde, J. L. (1976). Meaningful Processing of Sentences. In Singer, H. & Ruddell, R. B. (Eds.). Theoretical models and processes of reading (3rd ed.). Newark, Del.: International Reading Association. Henderson, J. M., & Ferreira, F. (1993). Eye movement control during reading: fixation measures reflect foveal but not parafoveal processing difficulty. Canadian Journal of Experimental Psychology. 47, 201–221. Hyönä, J., Niemi, P., & Underwood, G. (1989). Reading long words embedded in sentences: Informativeness of word halves affects eye movements. Journal of Experimental Psychology: Human Perception and Performance, 21, 68-71.


Slide18: References Eye movements and reading (cont.) Hyönä, J., & Olson, R. K. (1995). Eye fixation patterns among dyslexic and normal readers: effects of word length and word frequency. Journal of Experimental Psychology: Learning, Memory, and Cognition 21 (1995), 1430–1440. Inhoff, A. W. (1984). Two stages of word processing during eye fixations in the reading of prose. Journal of Verbal Learning and Verbal Behavior. 23, 612–624. Inhoff, A. W., & Radach, R. (1998). Definition and Computation of Oculomotor Measures in the Study of Cognitive Processes. In Underwood, G. (Ed.). Eye guidance in reading, driving and scene perception (pp. 29-53). New York: Elsevier. Just, M.A., & Carpenter, P.A. (1976). Eye fixations and cognitive processes. Cognitive Psycholgy, 8, 441-480.


Slide19: References Eye movements and reading (cont.) Nakayama, K., & Silverman, G. H. (1986). Serial and parallel processing of visual feature conjunctions. Nature, 320(6059). O’Regan, J. K. (1992). Optimal viewing position in words and the strategy-tactics theory of eye movements in reading. In: Rayner, K. (Ed.), Eye Movements and Visual Cognition, Scene Perception and Reading. New York: Springer-Verlag. Palmer, S. E. (1999). Vision science : photons to phenomenology. Cambridge, Mass.: MIT Press. Rayner, K., Fischer, M. H., & Pollatsek, A. (1998). Unspaced text interferes with both word identification and eye movement control. Vision Research, 38 (8), 1129-1144. Rayner, K., & Pollatsek, A. (1989). The psychology of reading. Englewood Cliffs, N.J.: Prentice Hall.


Slide20: References Eye movements and reading (cont.) Steinhauer, S.R., & Hakerem, G. (1992). The pupillary response in cognitive psychophysiology and schizophrenia. In: Friedman, D., and Bruder, G. (Eds.), Psychophysiology and experimental psychopathology: A tribute to Samuel Sutton. Annals of the New York Academy of Sciences, 658: 182-204. Vitu, F., & O’Regan, J. K. (1995). A challenge to current theories of eye movements in reading. In J.M. Findlay, R. Walker, & R.W. Kentridge (Eds.), Eye movement research: Mechanisms, processes and applications (pp. 381-392). North-Holland: Elsevier Science Publishers. Zelinsky, G., & Sheinberg, D. (1995). Why some search tasks take longer than others: Using eye movements to redefine reaction times. In J.M. Findlay, R. Walker, & R.W. Kentridge (Eds.), Eye movement research: Mechanisms, processes and applications (pp. 325-336). North-Holland: Elsevier Science Publishers.


References: References Webpage revisitation Abrams, D., Baecker, R., & Chignell, M. (1998). Information archiving with bookmarks: Personal web space construction and organization. In Proceedings of CHI '98. ACM Press, 4148. Cockburn, A., & Greenberg, S. (1999). Issues of Page Representation and Organisation in Web Navigation Tools. In Proceedings of the OZCHI'99 Australian Conference on Human Computer Interaction. Cockburn, A., Greenberg, S., Jones, S., McKenzie, B., & Moyle, M. (2003). Improving Web Page Revisitation: Analysis, Design And Evaluation. It&Society, 1(3),159-183. Cockburn, A., Greenberg, S., McKenzie, B., Smith, M., & Kaasten, S. (1999). WebView: A Graphical Aid for Revisiting Web Pages. In Proceedings of the OZCHI'99 Australian Conference on Human Computer Interaction.


References: References Webpage revisitation (cont.) Cockburn, A., & McKenzie, B. (2000). What do web users do? An empirical analysis of web use. International Journal of Human-Computer Studies, 54(6), 903-922. Jones, W., Bruce, H., & Dumais, S. (2001). Keeping found things found on the web. Proceedings of CIKM'2001, 119-126. Kassten, S., Greenberg, S., & Edwards, C. (2002). How people recognise previously seen web pages from titles, URLs and thumbnails, in Proceedings of HCI 2002, 247-265. Springer. Tauscher, L., & Greenberg, S. (1997). Revisitation Patterns in World Wide Web Navigation. In Human Factors in Computing Systems: Proceedings of the CHI '97 Conference. New York: ACM, 1997


Slide23: References Menu searching Altonen, A., Hyrskykari, A., & Räihä, K. (1998). 101 Spots, or how do users read menus? In Proceedings of CHI 98 Human Factors in Computing Systems, ACM Press, 132-139. Byrne, M.D., Anderson, J.R., Douglas, S., & Matessa, M. (1999). Eye tracking the visual search of clickdown menus. Proceedings of CHI 99, 402-409. NY: ACM Press. Hornof, A. J., & Kieras, D. E. (1999). Cognitive modeling demonstrates how people use anticipated location knowledge of menu items. In CHI '99 ACM Conference on Human Factors in Computing. 410-417 Ojanpää, H., Näsänen, R., & Kojo, I. (2002). Eye movements in the visual search of word lists. Vision Research, 42, 1499-1512.


Slide24: References Memory and salience Alba, J. W., & Hasher, L. (1983). Is memory schematic? Psychological Bulletin, 93, 203-231. Ashcraft, M. H. (1994). Human memory and cognition. New York, NY: HarperCollins College Publishers. Bartlett, F. C. (1932). Remembering. Cambridge: Cambridge University Press Clark, J. M., & Paivio, A. (1987). A Dual Coding Perspective on Encoding Processes. In McDaniel, M. A., Pressley, M. (Eds.). Imagery and Related Mnemonic Processes: Theories, Individual Differences, and Applications. (pp. 5-33). New York: Springer-Verlag. Cohen, G. (1996). Memory in the real world. Hove: Psychology Press.


Slide25: References Memory and salience (cont.) Desrochers, A., & Begg, I. (1987). A Theoretical Account of Encoding and Retrieval Processes in the Use of Imagery-Based Mnemonic Techniques: The Special Case of the Keyword Method . In McDaniel, M. A., & Pressley, M. (Eds.). Imagery and Related Mnemonic Processes: Theories, Individual Differences, and Applications. (pp. 56-78). New York: Springer-Verlag. Paivio, A., Yuille, J. C., & Madigan, S. (1968). Concreteness, imagery, and meaningfulness values for 925 nouns. Journal of Experimental Psychology Monograph Supplement, 76(1, Pt. 2), 1-25. Pointer, S. C., & Bond, N. W. (1998). Context-dependent memory: Colour versus odour. Chemical Senses, 23, 359-362.


Slide26: References Memory and salience (cont.) Rumelhart, D. E., & Norman, D. A. (1985). Representations of knowledge. In Aitkenhead, A. M., & Slack , J. M. (Eds.). Issues in Cognitive Modelling, pp. 15-62. London: Lawrence Erlbaum Associates Ltd. Soto, R. (1999). Learning and performing by exploration: Label quality measured by latent semantic analysis. CHI 99 Conference Proceedings, 416-425.


References: References Information management Lansdale, M. (1988). The psychology of personal information management. Applied Ergonomics, 19(1), 55-66.


Eye tracking tips: Eye tracking tips For more information go to: www.alexpoole.info or contact me at: alex@alexpoole.info