Figure 7.7 shows images from a recent eye-tracking study one of us conducted with a team of researchers in Nebraska (Ricci, Olson, & Smyth, 2013; Zhou, Smyth, & Olson, 2013). The black circles show the locations in which respondents fixated (i.e., their eyes paused on an area, in this case for a minimum of 100 milliseconds), while the numbers inside them indicate the order and duration of the fixations. Respondents are thought to be actively taking in information during fixations, but not when their eyes are moving between fixations (represented by the lines connecting the black circles) (Rayner, 1998). The grey circles represent mouse clicks, with the number inside them indicating the order in which they occurred. The top example in Figure 7.7 is from a respondent who skipped the first few words in the question stem, but thoroughly read the response options before registering an answer and advancing through the survey. The second example is from a respondent who only appears to have read one or two words in the question stem but then thoroughly processed the scale labels and each item within a grid and registered response for each item.