Using eye-tracking to identify pedestrians' critical visual tasks. Part 2. Fixation on pedestrians

This article investigates different approaches to the interpretation of eye-tracking video records of pedestrians walking outdoors to determine the apparent importance of fixation on other pedestrians and how this is influenced by the frequency of occurrence. The three approaches were as follows: the proportion of time that fixations were on pedestrians (14%), a common approach to interpretation; the proportion of fixations at critical moments that were on pedestrians (23%), critical moments being defined by a delayed response to a dual task; and the probability of an approaching pedestrian being fixated at least once (86%). These data were compared against the number of pedestrians encountered during the trials; the proportion of all fixations and the probability of fixating people were affected by the number of people encountered - only the critical-fixations data did not exhibit a trend.