. Author manuscript; available in PMC: 2020 May 1.

Published in final edited form as: Arch Dis Child Fetal Neonatal Ed. 2018 Jun 14;104(3):F259–F264. doi: 10.1136/archdischild-2017-314449

Table 1:

Visual attention parameters

Parameter	Description	Interpretation	Unit
Total Gaze Duration	Cumulative time each participant gazed on an area of interest, divided by the cumulative duration of gaze samples ^*	Where am I looking the most?	Percentage
Visit Count	Number of visits within an area of interest per 10 seconds	How often am I looking at an area?	Rate
Average Visit Duration	Average time spent in an area of interest on a single visit	When I do look at an area, how much time am I spending in that area?	Seconds
Gaze sample percentage	Number of eye tracking gaze points identified, divided by the theoretical maximum^**	How much of my gaze data is truly captured?	Percentage

The cumulative duration of gaze samples accounts for gaze sample percentage. i.e. if the entire recording lasted 100 seconds, but the gaze sample percentage was only 90%, the cumulative duration of gaze samples was 90 seconds

^**

The sampling frequency is 50Hz, so the theoretical maximum is 50 samples per second. If the software adequately identifies all 50-gaze samples within each minute, the value of gaze sample percentage would be 100%. Blinking usually causes 5–10% data loss.