jueves, 30 de junio de 2011

Papers en los que se ha usado el eyetracker de Tobii

La empresa Tobii va recogiendo periódicamente los papers académicos que se publican y para los que se ha utilizado su dispositivo.

La lista contiene casi 300 documentos, algunos en PDF, está en esta dirección:

lunes, 20 de junio de 2011

Some readings about Western and Eastern cognitive styles

Today I have resumed contact with a professor in Zayed University, Dr. Emad Bataineh, who I knew in the EyeTracking UX Conference in London (June 2011). We planned to do a research together and compare users's behavior in SERPs in two countries: Spain and UAE.

Looking for a start point I have found the PhD Thesis of Jolin Adeeb Qutub (director Frederick J. Brigham) who assess that "[...] Recent studies have concluded that Western learners tend to have more analytical perceptual learning style whereas East Asians tend to have more holistic or contextual perceptual learning style (Nisbett & Norenzayan, 2002). Only a limited number of studies have examined cognitive perceptual differences between Middle Eastern and Western learners. This study aimed to help close this research gap by exploring cognitive perceptual differences among three groups who come from different cultural backgrounds: Saudi Arabians, immigrants living in the United States, and Americans [...] ".

I have collected some references from the thesis:
  • Chua, H., Boland, J. and Nisbett, R. (2005). Cultural variation in eye movements during scene perception. Proceedings of the National Academy of Sciences, 102, 12629-12633
  • Masuda, T., & Nisbett. R. (2001). Attending holistically versus analytically: Comparing the context sensitivity of Japanese and Americans. Journal of Personality and Social Psychology, 81, 922–934.
  • Nisbett, R. (2004). The Geography of Thought: How Asians and Westerners Think Differently…and Why. New York: Free Press.
  • Nisbett, R., & Miyamoto, Y. (2005). The influence of culture: Holistic versus analytic perception. Trends in Cognitive Science, 9, 467-473
  • Nisbett, R.E., & Norenzayan, A. (2002). Culture and cognition. In H. Pashler & D. L. Medin (Eds.), Stevens Handbook of Experimental Psychology : Cognition (3d Ed., Vol. 2) (pp. 561-597). New York: John Wiley & Sons. [PDF]
  • Nisbett, R.E., Peng, K., Choi, I., & Norenzayan, A. (2001). Culture and systems of thought: Holistic versus analytic cognition. Psychological Review, 108, 291-310. [PDF]
  • Stevens, Handbook of Experimental Psychology, Vol 2. (3rd ed., pp. 561-597), New York: John Wiley and Sons, Inc.
  • Norenzayan, E., Smith, E., Beom, J., & Nisbett, R. (2002). Cultural preferences for formal versus intuitive reasoning. Cognitive Science, 26, 653–684.

And one more that I might need for this and other studies:
  • Hink, D. E., Wiersma, W., & Jurs, S. G., (1988). Applied Statistics For The Behavioral Sciences (2nd ed). Boston: Houghton Mifflin
If this study becomes a reality, I think the results can be very interesting. Let's see!

jueves, 16 de junio de 2011

Are you starting to read about Eyetracking in UX?

Basic readings:

Bojko, Aga, http://www.rosenfeldmedia.com/books/eye-tracking/blog/ Blog]

Bojko, Aga. & Stephenson, A. It's All in the Eye of the User: How eye tracking can help answer usability questions. User Experience, 4:1, 2005, http://www.usercentric.com/publications/2005/03/18/its-all-eye-user-how-eye-tracking-can-help-answer-usability-questions

Bojko, Aga. Using Eye Tracking to Compare Web Page Designs: A Case Study. Journal of Usability Studies, 1:3, 2006, http://www.upassoc.org/upa_publications/jus/2006_may/bojko_eye_tracking.pdf

Duchowski, A. T. A Breadth-First Survey of Eye Tracking Applications, 'Behavior Research Methods, Instruments, & Computers (BRMIC), 34:4, 2002, 455–470.

Duchowsky, Andrew. Eye Tracking Methodology: Theory and Practice (2nd ed). Springer, 2007. Part 3 “Eye Tracking Methodology", http://andrewd.ces.clemson.edu/book/toc.pdf

Goldberg, J.H.; Wichansky, A.M. Eye tracking in usability evaluation: A Practitioner's Guide. En: Hyona, J., Radach, R., Duebel, H (Eds.). The mind's eye: cognitive and applied aspects of eye movement research. Boston, North-Holland / Elesevier, 2003, 573-605.

Hassan Montero, Yusef; Herrero Solana, Víctor. Eye-Tracking en Interacción Persona-Ordenador, No Solo Usabilidad, 2007, http://www.nosolousabilidad.com/articulos/eye-tracking.htm

Nielsen, Jakob; Pernice, Kara. Eyetracking web usability. New Riders, 2010, http://www.useit.com/eyetracking/

Pernice, Kara; Nielsen, Jakob. Eyetracking Methodology: 65 Guidelines for How to Conduct and Evaluate Usability Studies Using Eyetracking, http://www.useit.com/eyetracking/methodology/eyetracking-methodology.pdf (16 Mb)

Poole, A.; Ball, L.J. (2004). 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, http://www.alexpoole.info/academic/Poole&Ball%20EyeTracking.pdf

Spool, J. Eyetracking: Worth The Expense?. UIE Brain Sparks Blog, 2006, http://www.uie.com/brainsparks/2006/06/13/eyetracking-worth-the-expense

Tullis, Tom; Albert, Bill. Measuring the user experience. Morgan Kaufmann, 2008, http://www.measuringux.com/

Usolab (2007). La aportación del eyetracking en el sector de usabilidad, 2007, http://www.usolab.com/articulos/eyetracking-usabilidad-comunicacion.php

What accuracy and precision means for eye trackers

Brilliant explanation from Aga -she again, sorry I admire her.

Accuracy and precision are not synonyms words. She explains both at http://www.rosenfeldmedia.com/books/eye-tracking/blog/the_most_precise_or_most_accur/:

"The accuracy of an eye tracker is the average difference between what the eye tracker recorded as the gaze position and what the gaze position actually was. We want this offset to be as small as possible but it is obviously unrealistic to expect it to be equal to zero. Accuracy is measured in degrees of visual angle. Typical accuracy values fall in a range between 0.5 and 1 degree."

(aka "spatial resolution") is a measure of how well the eye tracker is able to reliably reproduce a measurement. Ideally, if the eye is in the same exact location in two successive measurements, the eye tracker should report the two locations as identical. That would be perfect precision. In reality, precision values of currently available eye trackers range from 0.01 to 1 degree. These values are calculated as the root mean square of the distance (in degrees of visual angle) between successive samples.

Eyetracker simulation: EyeQuant, Feng-GUI, and Attention Wizard

These three software try to emulate the ocular behavior considering the elements showed on the screen.

Despite promising good results, some tests show that they are very far away from the reality. Aga shares their own results testing Ebay:

A main error would be that "For example, the simulations predict a lot of attention on images (including advertising), whereas the study participants barely even looked at many of those elements"

Behavioral and Physiological Metrics

This Chapter 7. of Tullis and Albert, Measuring the user experience, it worth reading although it will not easy to apply in UX tests. A list of the metrics:

1. Just observing and coding behaviors taking notes in a form or in a open format, verbal and non-verbal ones (see form on page 170)
1.1. Verbal comments: positive/negative comments, doubts, questions...
1.2. Non-verbal behaviors to analyze: facial expressions and body language

2. Using specific devices
2.1. Facial expressions
- Video recording analysis (time consuming), and classify them, ex. FACSAID 2002
- Electromyogram sensors (EMG), specially for forehead and cheeks
2.2. Body language to measure stress-frustration and engagement
- Mouse gripping
- Chair pressure
- Skin conductance
- Heart rate
- Pupil dilation
2.3. Eye tracking
- Proportion of users looking at a specific element or region (AOI*)
- Time spent looking at a specific element or region (AOI)
- Time to notice a specific element or region
- Scan-paths and length of eye movements

*Tips about AOIs:
- do not leave any space undefined
- analyze the time as a percentage of total time spent on the page, not as an absolute amount of time, since it can vary widely between participants