Nov 19, 2019
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.
There are several parts to eye-tracking. The first is saccades, the rapid eye movements made during reading that don't always follow left-to-right. 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, which are fixed moments when the eyes are concentrated on a particular location, and blinking.
An important piece of eye-tracking that has been around for decades but has only recently become easier to study 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 also an autonomic bodily response. Unlike breathing or heart rates, which can be 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. Jay walks us through the TCE formula in the podcast.
Mr. Thomas was a science teacher for 19 years and also worked for Kaplan Test Prep before coming to ACT.