How Google Instant was tested

Part of the user experience assessment for the Google Instant research required the labs to track the eye movement of the participants, reports CNET. Lasers mounted in the frame of the monitor emit light, and that reflected light is able to track the eye movements around the screen, identifying where the user's attention is being directed.

Here, the red line maps the path of the eyes, and the larger red ball shows the current point of focus. Read more