| Fixation count |
The number of fixations in the AOI, averaged per participant per clip. High fixation count can be indicative of higher cognitive effort and/or poorer reading skills. |
| Mean fixation duration |
The duration of a fixation in a subtitle AOI, averaged per clip and per participant. Longer mean fixation duration may be an indication of higher cognitive load. |
| Absolute reading time |
Dwell time, i.e., the sum of durations of all fixations and saccades in an AOI starting with the first fixation. Longer reading time may be related to processing difficulties. |
| Proportional reading time |
The percentage of dwell time a participant spent in the AOI as a function of subtitle display time. For example, if a subtitle lasted for 3 seconds and the participant spent 2.5 seconds in that subtitle, the percentage dwell time was 2500/3000 ms = 83%, i.e. while the subtitle was displayed for 3 seconds, the participant was looking at that subtitle for 83% of the time. This measure allowed us to compare the proportion of time spent in the subtitles between different conditions. If proportional reading time approaches 100%, it means that participants spent most of their time reading subtitles and did not have time to look at on-screen action. |
| Revisits |
The number of glances a participant made to the subtitle AOI after visiting the subtitle for the first time. Revisits may indicate a more disruptive reading process, as the participant goes back to read the AOI they had already read, for instance because of text difficulty or because the subtitle is displayed for too long. |
