As Google points out, most people are not conscious of their eye movement, especially when doing something as mundane as a web search. Eye-tracking data lets you identify which elements of a webpage (or other stimulus) are viewed, and in what order. Just as importantly, you can identify elements that are not viewed - which may be the reason why task completion, ad recall or messaging breaks down.
In my opinion, eye-tracking is most powerful when it is combined with traditional think-aloud usability protocol. At Sentient, we do this with a little bit of a twist - first we start by allowing the user to complete a series of tasks without interruption from us to capture task completion and eye-tracking data without interference from trying to hold a conversation as well. Then we have the user walk us through what they were thinking and doing in a qualitative debrief.
By delving into a qualitative debrief after a user completes a task while their eyes are tracked we can learn the why behind what they did. For example:
- Did they linger on an element because it intrigued them or confused them?
- Why did they look at one navigation element, but then move to other navigation elements and click on them?
By adding eye-tracking to the usability arsenal, you get a rich interaction between the quantitative eye-tracking metrics and the qualitative insights derived from traditional usability methods.