Hazard anticipation of young novice drivers - SWOV

Besides significance of the results, the effect size (Partial èta squared, η 2 P
)
was considered with η 2 P
= .01 as a small, η 2 P
= .06 as a medium, and η 2 P
= .14
as a large effect size (Cohen, 1988). To indicate the effect size of the results of
χ 2 tests the value of Cramer's V is presented.
4.3. Results
4.3.1. The hazard detection and recognition task
Anticipatory eye glances
If participants fixated a latent hazard 9 , there were no significant differences
between the three groups (young learner drivers, older learner drivers and
experienced drivers) in the moment of the first fixation, the duration of the
first fixation, the number of fixations on the latent hazard, the total time of
the fixation durations, the moment of the last fixation and the duration of the
last fixation. However, there were differences between the groups whether a
latent hazard was fixated at all (at least one fixation of 200 ms or more) or
was not fixated. Table 4.1 contains the percentages of participants in a group
that had at least one anticipatory fixation in the areas of each covert latent
hazard and each overt latent hazard within the timeframes of each latent
hazard. See for a description of the latent hazards Appendix 1. C1 means
covert latent hazard 1 in Appendix 1 and O1 means overt latent hazard in
Appendix 1. To test if the scores for each area differed significantly between
the three groups, the χ 2 test was applied. For three covert latent hazards and
eight overt latent hazards the assumptions for the χ 2 test were not met.
9
A fixation was valid when it lasted at least 200 ms and was in the (moving) area of a latent
covert hazard (all together six areas) or a at a (moving) latent overt hazard (all together ten
areas) within the particular timeframe of that latent hazard.
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