Behavioral and Physiological Metrics - Measuring the User Experience: Collecting, Analyzing, and Presenting Usability Metrics - page 170

By far the most common way to visually represent eye movement for multiple
participants is through a heat map (see Figure 7.7 ). In this visualization, the brightest
areas (red) represent a greater density of fixations. It is an excellent way to get a sense
of what areas of the page attract more (and less) visual attention. It is important to
keep in mind that the analysis software allows the researcher to define the scale of
what is considered “red” versus “orange,” etc. So, beware that the researcher can eas-
ily exaggerate the heat maps to show more or less color. We recommend using the
default settings on most software; however, it is important to experiment with using
different scales. The opposite visualization is called a focus map, which makes trans-
parent those areas that received more visual attention and darkens those areas that
received little or no visual attention. In some sense, a focus map is more intuitive,
but a little less common since it is hard to see those areas that are ignored by users.
Figure 7.7 Example of a heat map of the Amazon Video website showing the distribution of eye movements across all participants in
the study. The brighter areas as shown in red, orange, and yellow received relatively more visual attention.
7.2.3 Areas of Interest
The most common way to analyze eye-tracking data is by measuring visual atten-
tion on specific elements or regions. Most researchers are not just interested in
how visual attention is distributed across a web page or scene, but whether par-
ticipants noticed certain things and how much time was spent looking at them.
This is particularly the case in marketing, whereby the success of an ad campaign