Little empirical evidence can be found in the visual occlusion literature to justify decisions about how glance durations should be fixed for self-paced visual occlusion investigations. This paper presents a hypothesis about how glance duration may affect performance, based on a theory of how uncertainty develops as an operator’s vision is occluded and how it is resolved during visual glances. Data are analysed from two on-road driving experiments involving a range of fixed glance durations. The analysis is repeated with data collected from an analogous study in a low fidelity driving simulator. Both analyses support the hypothesis that increasing glance duration may prolong achievable mean occlusion times, but only up to a certain point, after which essentially no changes are expected. The paper concludes with a practical recommendation for selecting fixed glance durations for (self-paced) visual occlusion studies. (Author/publisher)
Abstract