What is eye tracking? Eye tracking is the process of electronically locating the point of a person's gaze, or following and recording the movement of the point of gaze. It is based on the mind-eye hypothesis - it states what people are looking at and what they are thinking about tends to be the same. In a usability test, eye tracking is used to see what design elements participants are concerned about - the more they look at something, the more they think about it.
Why is it important? Eye tracking is a powerful tool for user experience professionals to consider adding to their usability test plan because the data captured is precise, engaging and actionable. The heatmaps and gaze plots generated during eye tracking of a participant's fixations while they are completing a task is powerful scientific evidence. The results are striking and engaging because looking at hotspots or tracking the movement of an eye can be quickly understood by project stakeholders. The realistic tasks that participants perform will point exactly to the locations the users did or did not find information to complete their goal. Time on task and viewing time can be mapped precisely.
When should it be used? Using eye tracking as part of a usability study is suggested on a case-by-case basis because it should compliment other observations and project goals. Per an article from UX Mag, "Combined with talk-aloud usability testing, eye tracking can help complete the research picture by supplementing what users say with what they see." Incorporating eye tracking into usability testing helps reduce distractions by usability researchers because the participant is focused on doing the usability task. Furthermore, it will reduce the chances of a participant adjusting their answers to make the more favorable to the researcher. Consider adding eye tracking in your usability toolkit if it adds to your results.
