Author: Ali Enright
Enright, Ali, 2018 Collaborative Visual Search, Flinders University, College of Education, Psychology and Social Work
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This thesis shows work that largely aims to better understand collaborative visual search. More specifically, we aimed to replicate previous findings of collaborative search performance, that is, performance that meets or exceeds the predictions of a uniform weighting model of information integration and extend them to a signal detection task using naturalistic stimuli. We also aimed to investigate a collaborative search strategy when little target information is available to observers.
In the first study, searchers performed a simulated baggage screening task and attempted to detect a target (one of a possible 5 knives) in x-ray baggage images. In Experiment 1, single observers completed the task in separate testing rooms, and teams collaborated in the same testing room. In Experiment 2, single observers and teams completed the task in the same testing room. In Experiment 3, both single observers and teams completed the search task in separate testing rooms. In Experiment 4, finally, single observers and teams were collocated, and stimuli presentation time was fixed (3s). In all four experiments, teams outperformed single observers and achieved sensitivity levels roughly midway between the predictions of the two versions of the uniform weighting model. A meta-analysis using the data from all four experiments confirmed this pattern of results.
In the second study, observers performed a visual search task framed as a medical image reading task and attempted to locate an ‘abnormal cell’ amongst other normal ‘cells’. Top-down target information was limited by using dot-distortion stimuli. In Experiment 1, single observers completed the task in separate testing rooms and team collaborated in the same testing room, whereas in Experiment 2, both single observers and teams completed the search task in separate testing rooms. Teams outperformed single observers in both experiments and collaborative sensitivity again fell in between the predictions of the two versions of the uniform weighting model.
The most consistent finding in both Studies 1 and 2 is that collaborative searchers outperform single seachers. Some of our findings show that teams can even outperform what is expected given their individual sensitivity levels and the similarity between team members’ judgments. Such findings suggest that teams might adopt visual search strategies that work to decorrelate their judgments, resulting in a larger collaborative benefit when integrating their judgments. Another implication of our findings is that non-collocated teams can perform similarly to collocated teams. Finally, we provide evidence that collaboration under conditions of limited target information is valuable.
Keywords: Collaborative visual search, signal detection, decision making
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
Completed: 2018
School: College of Education, Psychology and Social Work
Supervisor: Mike Nicholls