Table 6.
Comparison of eye-movement measures computed with algorithms that use individual and task-specific, respectively, only task-specific velocity thresholds
| Measure | Statistic | Overall | Reading | Search | Ad exploration |
|---|---|---|---|---|---|
| Number of fixations | Mean difference | –1.53 | –2.78 | –.32 | –1.26 |
| MAD | 19.27 | 46.15 | 4.16 | 5.82 | |
| MAPD | .21 | .27 | .18 | .18 | |
| Correlation | .90 | .55 | .92 | .84 | |
| Fixation durations (ms) | Mean difference | 1.24 | –.02 | –2.14 | 4.65 |
| MAD | 56.98 | 71.15 | 55.85 | 45.26 | |
| MAPD | .22 | .26 | .22 | .19 | |
| Correlation | .14 | –.08 | .38 | .07 | |
| Saccade size (°) | Mean difference | –.01 | –.00 | –.06 | .02 |
| MAD | .56 | .34 | .63 | .70 | |
| MAPD | .17 | .18 | .17 | .16 | |
| Correlation | .89 | .59 | .82 | .69 |
Note: The reported statistics are: mean difference: the overall mean for the eye-movement measure in question, computed using individual specific velocity thresholds minus the overall mean computed using the average velocity threshold for individuals, within a specific task; MAD Mean absolute deviation of the measures computed using individual and average velocity thresholds; MAPD Mean absolute percentage deviation of the measures computed using individual and average velocity thresholds; Correlation Correlation coefficient of the measures computed using individual and average velocity thresholds