Abstract
Visual search is often a collaborative process. For instance, pairs of individuals will search luggage during security checks and physicians will collaboratively search for abnormalities in x-ray images. In three experiments we compared the search performance of two people searching together (collaborative condition) with the pooled performance of the two individuals searching separately (nominal condition). In Experiment 1, search in the collaborative condition was compared to search in a nominal condition in which the individuals worked separately and at the same time (i.e., in parallel). In Experiments 2 and 3, search in the collaborative condition was compared to search in a nominal condition in which pairs worked sequentially. Experiment 2 was designed to simulate security search and so any targets found by the first individual in the nominal pair were removed so that the second individual received fewer target items. Experiment 3 was designed to simulate medical diagnosis of X-rays by providing the second searcher in the nominal pairs with the responses given by the first searcher in the pair. In all experiments collaborative pairs were less likely than nominal pairs to correctly detect a target and they were less likely to make false alarms. Additionally, signal detection analyses revealed that collaborative pairs were more sensitive to the presence of the target and had a more conservative response bias than the nominal pairs.
This research was supported by a grant to D.S., a postdoctoral fellowship to M.G.R. and a graduate scholarship to K.A.M from the Natural Sciences and Engineering Research Council (NSERC).