The document summarizes an eye tracking study presented at the Association for Business Communication's 78th Annual International Convention in New Orleans, 2013. The study consisted of three parts: (1) an introduction to foundational eye tracking concepts and approaches to website navigation, (2) a discussion of the Webby Awards and an eye tracking study of various website genres, and (3) limitations and strengths of eye tracking technology. Key findings included that task-based eye movements still follow patterns like the Golden Triangle and F-Pattern but are influenced by current web conventions, and stimulated retrospective think aloud is a valid method for gathering qualitative user data during eye tracking studies.

1. Association for Business Communication
78th Annual International Convention
New Orleans, 2013
Tharon Howard,
Clemson University UsabilityTesting Facility Director
tharon@clemson.edu

2. Part One: An Introduction to Eye Tracking Foundational
Concepts and Two Approaches to Website Navigation
(Tharon)
Part Two: Webby Awards and an Eye Tracking Study
(Heather)
Part Three: Limitations and Strengths of Eye Tracking
(Brian)

3. Fovea
Saccades
Fixations
Parafovea
How FovealVisionWorks

4. Example of FovealVision
Source: http://themetapicture.com/it-was-worth-it/

5. FovealVision
Instead of:
Credit: Dan Liddle, Clemson UTF

6. FovealVision
We can only see:
Credit: Dan Liddle, Clemson UTF

7. FovealVision
We can only see:
Credit: Dan Liddle, Clemson UTF

8. FovealVision
We can only see:
Credit: Dan Liddle, Clemson UTF

9. FovealVision
We can only see:
Credit: Dan Liddle, Clemson UTF

10. Saccades and Fixations
Can be as short as 20 milliseconds or
as long as 200 milliseconds
The fastest movement produced by
the human body
Substantial image blur during a
saccade due to this speed
fixation fixation
saccade
Fixation: Eye-movement pauses to acquire
Content
Saccades: The period of eye-movement from
one fixation to the next

11. AlfredYarbus –TheVisitor (1967)
Saccades are not
arbitrary; they’re
influenced by
parafovea vision
Users’ tasks and
goals play a
significant role in
the gaze plot

12. “Depth of Processing” Gaze Plot

13. • “Mechanical” or Search Coil
• “Glint” or Dual Purkinje
• Limbus or PupilTracking
• Dual-PointVideo
Popular EyeTracking
Technologies to Consider

14. Search Coil & Magnetic Field
or “Mechanical”
Uses contact lenses
with search coils and
a magnetic field
Usually combined with reflected light
Extremely accurate
Very costly
Uncomfortable & not portable
Source: http://www.iovs.org/content/44/1/275.long

15. Dual Purkinje Image
or “glint”
Uses infrared light to create reflections from
different parts of eye
Video tracks 2 reflections and software
calculates angles
Good accuracy
Comfortable for users
Allows more head movement
Still costly
Source: http://www.fourward.com/dconcept.htm
Source: http://medical-dictionary.thefreedictionary.com/Purkinje-
Sanson+mirror+images

16. Limbus or PupilTracking
or “Single-PointVideo-Based”
Image processing of video is used to locate pupil
and calculate POG
A Starburst algorithm projects rays from an initial
starting point detecting pixels with high image
gradients
Source: Howard & Sulak
Example of rays projected from initial point
Source: Ryan, Duchowski, & Burchfield

17. “Dual-PointVideo-Based”
Image processing tracks pupil and corneal reflection
of IR light is also tracked
Less expensive
Comfortable
Head movement is limited
Only accurate to 1-2 degrees (1o is about 0.5”
at 27” distance)
Example of rays projected from initial point
Source: Ryan, Duchowski, & Burchfield
Source: Howard & Sulak

18. Some OtherTerms to Know
Accuracy—Measured in degrees and typically ranges from 0.5
to 2 degrees. Keep in mind that 1o is about half an inch of
resolution at the normal 27” viewing distance for computer
monitors.
Precision—Smallest change in eye position that can be
measured. Usually this is also measured in fractions of
degrees.
Sampling Rate—Measured in Hertz, this factor is important
because eye movements are the fastest humans can produce.
Over 1000 Hz is needed to capture many eye movements, but
most systems typically run at 50 to 60 Hz.

19. The “F Pattern” and Golden
Triangle
Source: http://blog.mediative.com/en/2011/08/31/eye-
tracking-google-through-the-years/
Source: http://www.nngroup.com/articles/f-shaped-pattern-reading-web-content/
“Eyetracking visualizations
show that users often read
Web pages in an F-shaped
pattern: two horizontal
stripes followed by a vertical
stripe.” Jakob Nielsen
“We recorded how 232 users
looked at thousands of Web
pages.We found that users'
main reading behavior was
fairly consistent across many
different sites and tasks.”
Found consistent pattern
from 2005 - 2011

20. Rosenblatt and Web Page Genres
Efferent(to carry away) Aesthetic (emotional pleasure)
“In readings that fall somewhere in the efferent half of
the continuum, the reader selects out predominantly
more public or cognitive elements than private.The
aesthetic stance, in contrast, accords selective
attention to predominantly more of the penumbra of
private feelings, attitudes, sensations, and ideas than
to the public aspects.” Louise Rosenblatt
Source: “TheTransactionalTheory:Against Dualisms.” College English,Vol. 55, No. 4. (Apr., 1993), p. 383.

21. Rosenblatt and Gaze Plots
Efferent(to carry away) Aesthetic (emotional pleasure)
Do the GoldenTriangle and F-Pattern
obtain for “aesthetic” sites as well as
for “efferent” sites?

22. Tharon Howard, Clemson UsabilityTesting Facility Director
tharon@clemson.edu
Part One

23. Honoring the Best of theWeb
Source: http://www.grumpycats.com/grumpy-cat-wins-meme-
of-the-year-at-the-17th-annual-webby-awards/#.UmiDsyToVWZ
Source: http://www.webbyawards.com/press/

24. Source: http://www.morethanamap.com/
Google More than a Map – Efferent
(Transactional)

25. HuffPost Live - Aesthetic
Source: http://live.huffingtonpost.com

26. EyeGuide®Tracking System
EyeGuide® Hardware:
• Camera
• LED
• 2.4 GHz transmitter
Source: http://www.otshow.com
Source: Howard,Christiansen & Gaines

27. Calibrating the EyeGuide®
Source: Howard,Christiansen & Gaines
Source:T. Howard

28. Research Question:
• Do users' eye movement patterns differ between websites which are
designed to provide users with information (efferent/ transactional) versus
websites which are designed to provide users with aesthetic experiences?
Preparing for the Study
Participants:
• 21+ in age with a bachelors degree or higher
• Recruited a convenience sample
• Goal of 10 participants
• Approximately 30 – 45 minutes/ participant

29. Fit participant with the head-mounted eye tracking device.
Study Procedures
Calibrate the eye tracker.
After a satisfactory calibration, begin tasks.
Participant is shown a series of ten screen captures from website interfaces.
Each screen capture is assigned a specific task.
While completing tasks, the EyeGuide® software captures eye movement data.
Stimulated RetrospectiveThink Aloud: after completing the tasks, the
participant is shown gaze plots of his or her eye movements and asked a series
of questions.

30. Gaze Plots
Source: Howard,Christiansen & Gaines

31. Heat Maps
Source: Howard,Christiansen & Gaines

32. Stimulated RetrospectiveThink Aloud
Source: Howard,Christiansen & Gaines

33. Task-based eye tracking - the Golden
Triangle and F Pattern are still present,
but current web conventions tend to
dominate the gaze.
What DidWe Learn?
Source: Illustration adapted fromYarbus
1967, figure 109, for Land andTatler 2009

34. “Commenting Policy”Task
All Participants

35. Source: Howard,
Christiansen & Gaines

36. Source: Howard,
Christiansen & Gaines

37. Heather Christiansen, PhD Student
Rhetorics,Communication and Information Design
Clemson University
hdunn@clemson.edu
Part Two

38. Brian Gaines,
Graduate Research Assistant,
Clemson University
blgaine@g.clemson.edu

39. EyeTrackers can be expensive.This
usedTobii T120 system is $27,500.
(Image courtesy of eBay, inc.)
SensoMotoric Instruments (SMI) Eye
Tracking Glasses 2.0 are priced on a
case by case basis.This could
potentially be quite costly. (Image
courtesy of SensoMotoric Instruments,
GmbH)
Price

40. Lab costs, as well as the costs for participants can be costly. For example,
Eye Tracking, Inc. charges between $5,000-$250,000 per study.These costs
are determined by the type of study, length of study, number of participants,
etc.
Price

41. The Grinbath Eye Guide is roughly $2,495, with discounts
applied to multiple unit purchases. (Image courtesy of Grinbath,
LLC)
Affordable options are available.

42. Eye Tribe’s USB 3.0
Hardware is only $99, but
comes with a Software
Development Kit (SDK),
which means code must be
written in order for this
device to be used. While the
base price is attractive, the
time and cost of hiring a
software engineer is
something to consider.
But, how affordable is affordable?

43. Equipment Sensitivity
Because of the sensitivity of the equipment, the
participants were uncomfortable. (Image Courtesy of Brian Gaines)

44. Equipment Sensitivity
Calibrating the eye tracker is in itself an art and a science.
(Image courtesy of Tharon W. Howard, Ph.D.)

45. Equipment Sensitivity

46. Differences in Participants

47. Retrospective think aloud is a technique used in usability,
and eye tracking in particular, to gather qualitative
information on the user intents and reasoning during a
test. It's a form of think aloud protocol performed after
the user testing session activities, instead of during them.
Fairly often the retrospective protocol is stimulated by
using a visual reminder such as a video replay.
(Guan, Lee, Cuddihy, and Ramey, 2006)
Stimulated RetrospectiveThink Aloud

48. More than 80% of subjects’ verbalizations of what they
were attending to corresponded with the eye movement
data. We reject the notion of subjects’ fabrication since
only less than 3% of their verbalization failed to match up
with objects identified by their eye movement.
(Guan, Lee, Cuddihy, and Ramey, 2006)
Stimulated RetrospectiveThink Aloud

49. Immediately following the eye tracking session, the data is available.
Instantaneous Results

50. Instantaneous Results

51. Cons
• Certain eye tracking technologies are
expensive
• Lab/participants costs
• Equipment sensitivity
• Accommodating for differences in
participants
Pros
• As technology advances, prices
will drop
• Stimulated Retrospective Think
Aloud is a valid data collection
method
• Results are intantaneous
Conclusions