Measuring gaze overlap on videos between multiple observers

Abstract

For gaze-based training in surgery to be meaningful, the similarity between a trainee's gaze and an expert's gaze during performance of surgical tasks must be assessed. As it is difficult to record two people's gaze simultaneously, we produced task videos made by experts, and measured the amount of overlap between the gaze path of the expert surgeon and third-party observers while watching the videos. For this investigation, we developed a new, simple method for displaying and summarizing the proportion of time during which two observers' points of gaze on a common stimulus were separated by no more than a specified visual angle.