Eye Tracking for Usability


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Eye Tracking for Usability

  1. 1. Eye Tracking for Usability<br />A Primer for User Experience Professionals<br />
  2. 2. Agenda<br />
  3. 3. Introduction<br />Hi!<br />Dan Berlin, MBA, MSHFID<br />@banderlin<br />dan@danielberlin.com<br />2 years researching neuromarketing methods<br /> - eye tracking, biometrics, neurology, emotions<br />
  4. 4. Eye Tracking Vendors<br />Two main players: &<br />Tobii<br />Based in Sweden, offers the same equipment for scientific research, & has assistive technology products<br />SMI<br />Based in Germany, offers high-end & integrated equipment for scientific research<br />
  5. 5. Eye Trackers<br />1750<br />T60/120<br />T60 XL<br />X60/120<br />Tobii Glasses<br /><ul><li> 1750 & X60: old technology is old
  6. 6. T60 & XL: depends on your needs
  7. 7. Glasses: brand new
  8. 8. depends on IR markers
  9. 9. only 30 Hz
  10. 10. small DVR
  11. 11. You probably don’t need 120 Hz
  12. 12. Tobii studio and Axure wireframes do not play nicely together</li></li></ul><li>Eye Trackers<br />RED<br />iView X HED<br /><ul><li> RED
  13. 13. 60/120 Hz (also have 250 Hz model)
  14. 14. Use a screen up to 300”
  15. 15. iView X HED
  16. 16. Up to 200 Hz
  17. 17. Uses a notebook or subcomputer
  18. 18. No IR markers
  19. 19. Germaphobes: gotta clean that hat
  20. 20. Software advantage: moving AOIs & better statistical analysis</li></li></ul><li>When is Eye Tracking Appropriate?<br />The age old question…<br />In usability studies<br />NOT during think-aloud<br />It is natural for a participant to look at the moderator<br />And they will look at parts of the screen that they are talking about<br />Does retrospective think-aloud alleviate this?<br />It asks participants to remember what they were unconsciously thinking<br />More likely: primacy and recency effects (Michael Summers, TrueAction)<br />Allocate a few tasks to eye tracking where the user does not think-aloud<br />Avoid bias: make up a story for the calibration<br />
  21. 21. When is Eye Tracking Appropriate?<br />In benchmark studies<br />Comparing user behavior to different design or interaction concepts<br />No think-aloud, just explore the site<br />Can be done with a static composition or a wireframe<br />Compare, compare, compare – there are no benchmarks<br />Use metrics to determine if participants are looking at areas of interest<br />Not all AOIs are equal – some should be more important to the business<br />Static pages: 10 to 20 second exposure<br />Otherwise: the big red blob – they look everywhere<br />
  22. 22. Eye Tracking Output<br />The typical outputs from eye tracking:<br />Fixations & duration<br />Time to 1st fixation<br />Gaze plots & heat maps<br />Areas of interest (AOIs)<br />Pupil dilation<br />But first, some information from a study published the Journal of Advertising Research<br />
  23. 23. Attentive vs. Emotive Advertising<br />Measured fixations per second (FPS) for two types of television ads<br />Attentive = top-down processing<br />Emotive = bottom-up processing<br />They found that the different types of ads were just as effective at different levels of attention (FPS)<br />Attentive = high # of fixations<br />Emotive = low # of fixations<br />So, we must consider what we are testing when examining the data<br />Interactive Web sites necessarily require high attention<br />vs.<br />Heath, Nairn, & Bottomley. (2009) “How Effective is Creativity? Emotive Content in TV Advertising Does not Increase Attention.” Journal of Advertising Research. 49(4). 450-463.<br />
  24. 24. Eye Tracking Metrics<br />Fixations vs. duration<br />Basically, they are the same<br />Both measure levels of active attention and cognition<br />We will never know if an increased duration indicates confusion or interest<br />Fixations per second is the traditional measure of active attention<br />Gaze plots and heat maps<br />Eye candy and not much else – but clients love them<br />Bolster your eye candy with data!<br />Pupil dilation<br />Impossible to measure accurately – don’t use it<br />
  25. 25. Ok, so how should I use eye tracking metrics?<br />Use areas of interest to compare metrics<br />How many fixations are in (un)important AOIs?<br />Will determine if an important AOI needs more emphasis<br />How do fixations in similar AOIs compare between different design treatments?<br />Will determine which design better achieves business goals<br />How long does it take participants to get to a particular AOI? (time to 1st fixation)<br />You only have a few seconds to impress a user – are they looking at that which you want them to?<br />
  26. 26.
  27. 27. Participant Recruitment<br />Make sure you ask about eye ailments<br />Retina & cornea damage, eye cancer & tumors, macular degeneration, cataracts, conjunctivitis, and nystagmus<br />Not necessarily problematic: amblyopia, glaucoma, and strabismus<br />If possible, you want to use the data from everyone you bring in<br />Add questions to your screener to ensure you can eye track your participants<br />
  28. 28. War Stories<br />The most frustrating thing about eye tracking: losing the signal<br />You’ll get a good calibration, the data starts off nicely, then the user changes position and <poof>, there goes the eye tracking<br />What do you do?<br />“Since you are watching where I’m looking, I was trying not to look in some areas.”<br />Sometimes, the eye tracking data will inform you which participant should be shown the door<br />
  29. 29. Creep Map<br /><ul><li> 1 minute exposure
  30. 30. These are the only hotspots on the entire page
  31. 31. When asked why this design comp was given a low rating, the response: “because she’s fat”
  32. 32. Oy vey</li></li></ul><li>Q & A<br />What are your eye tracking experiences?<br />What have you found to be useful or annoying?<br />What other metrics do you use?<br />Thanks for having me!<br />