Week 5 Flashcards
(17 cards)
What is “eye tracking” more accurately called?
Gaze tracking: measuring where a person is looking, for how long, and in what sequence.
What three primary measures does eye tracking provide?
Point of regard (focal point), fixation duration, and gaze sequence.
Name four major applications of eye tracking.
UX research, academic research (psychology, linguistics), marketing research, assistive technology, gaming, automotive, medical diagnostics.
What distinguishes desktop eye trackers from wearable eye trackers?
Desktop trackers are mounted on or below a monitor for controlled, high-precision studies; wearable trackers are glasses/headsets for mobile, natural-environment testing.
Describe the basic PCCR (Pupil Centre Corneal Reflection) method.
Infrared illuminators create glints on the cornea; a camera captures pupil and glint; software computes the vector between pupil centre and corneal reflection to infer gaze direction.
What advantage does Tobii’s 3D eye model provide over traditional PCCR?
Tolerates head movement in all directions and maintains accuracy across eye shapes and positions.
Contrast dark-pupil vs. bright-pupil tracking.
Dark-pupil: illuminator off-axis, pupil appears darker; bright-pupil: illuminator on-axis, creates red-eye effect.
What is involved in the eye-tracker calibration process?
User fixates on a series of targets (often 9); system records glint-pupil vectors; build interpolation mapping vectors to screen co-ordinates.
Define a “fixation” in eye-movement research.
A period (≈200–300 ms) when gaze is relatively still and information is processed; depicted as a circle sized by duration in visualizations.
What is a “saccade”?
A rapid eye movement (≈30–80 ms) between fixations during which no information is processed; shown as lines between fixation points.
How does a gaze plot differ from a heat map?
Gaze plot: Shows individual fixation order and duration; Heat map: aggregates across users, with colour intensity indicating attention concentration.
List three factors that can degrade tracking quality.
Bright ambient light, eyeglass reflections, bifocal lenses, heavy makeup, excessive head movement.
What best practices improve eye-tracking data quality?
Control lighting, positions participants properly, perform through calibration
Outline the main stages of an eye-tracking UX study.
Planning (questions & metrics), recruitment, task design, data collection (with complementary methods), analysis, insight generation.
What is “Time to First Fixation” and what does it indicate?
The time until a user first looks at an element; indicates how quickly key items attract attention.
Explain “Areas of Interest” (AOIs).
Predefined regions on stimuli; used to quantify and compare where and how long users look within those regions.
What limitations should researchers be aware of when using eye tracking?
“Look but not see” phenomenon, Hawthorne effect, interpretational ambiguity, technical challenges with certain populations.
