Validating Cognitive Processes with Eye-tracking

Podcast Episode 5: Eye-tracking with Jay Thomas

In this episode, guest Jay Thomas, Senior Assessment Designer at ACT, discusses how eye-tracking can go beyond psychometrics to evaluate and validate assessment and testing.

[If the player doesn’t load, listen or read a transcript of the show at: https://actnext.org/research-and-projects/navigator-podcast-ep-5-eye-tracking/]

There are several aspects of recording and sampling eye movement. First are saccades, the rapid eye movements made during reading that don’t always follow left-to-right. Sometimes our eyes make retrograde saccades to backtrack text. It’s estimated that humans make over 100,000 saccades daily, including during rapid eye movement (REM) sleep cycles when we’re dreaming.

Other obvious parts are fixations, moments when the eyes are focused on a particular location, and blinking.

Another important piece of eye-tracking that has been around for decades is pupillometry, the measurement of pupil dilation.

Dilation can be interpreted to measure thinking and cognitive effort, in particular the size changes and acceleration of dilation. Pupil dilation is an autonomic bodily response. Unlike breathing or heart rates, which can be controlled or modified to trick lie detectors, you cannot “fake” or consciously control dilating your pupils.

Thomas says that eye-tracking goes beyond psychometrics to validate tests and give insight into cognitive thought processes. With Langenfeld, Zhu, and Morris, he created a formula to measure Total Cognitive Effort (TCE) for test items. He walks us through the TCE formula (above) in the podcast.

Before joining ACT, Mr. Thomas was a science teacher for 19 years and also worked for Kaplan Test Prep.

Read a transcript of the show at: https://actnext.org/research-and-projects/navigator-podcast-ep-5-eye-tracking/