Spatial and temporal separation fails to counteract the effects of low prevalence in visual search

Recent research has shown that, in visual search, participants can miss 30-40% of targets when they only appear rarely (i.e., on 1-2% of trials). Low target prevalence alters the behaviour of the searcher. It can lead participants to quit their search prematurely (Wolfe, Horowitz, & Kenner, 2005), to shift their decision criteria (Wolfe et al., 2007), and/or to make motor or response errors (Fleck & Mitroff, 2007). In this paper we examine whether the low prevalence (LP) effect can be ameliorated if we split the search set in two, spreading the task out over space and/or time. Observers searched for the letter "T" among "L"s. In Experiment 1, the left or right half of the display was presented to the participants before the second half. In Experiment 2, items were spatially intermixed but half of the items were presented first, followed by the second half. Experiment 3 followed the methods of Experiment 2 but allowed observers to correct perceived errors. All three experiments produced robust LP effects with higher errors at 2% prevalence than at 50% prevalence. Dividing up the display had no beneficial effect on errors. The opportunity to correct errors reduced but did not eliminate the LP effect. Low prevalence continues to elevate errors even when observers are forced to slow down and permitted to correct errors

Comparison of user performance in mixed 2D-3D multi-display environments

Stereoscopic displays and volumetric 3D displays capable of delivering 3D views have in use for many years. These standalone displays have been investigated in detail for their impact on users’ viewing experiences. Effects like aesthenopia and nausea are well-known for flat-screen based stereoscopic displays. However, these devices have not been tested in the context of multi-display environments (MDEs). The performance cost of repetitive switching between a 3D (stereo or volumetric) display and a standard 2D display are not known. In this paper, we perform a thorough user study where we investigate the effects of using such 3D displays within the context of a MDE. We report on our findings and discuss the implications of the same on designs involving such hybrid setups. Our experiments show that in the condition involving two 2D displays which allow for motion parallax and perspective correction, the participants performed the task the fastest