The role of familiarity and experience in the implementation of efficient visual search strategies

Imagine searching your office for your keys. You will likely start by scanning surfaces in your office such as your desk, table, and shelves. You may then check pockets, bags, and underneath papers, until you either find the keys or give up. How efficient was this search? How much time did you waste looking in places you already inspected, searching an area for too long, or looking in places that contained no useful information? In this proposal, we define search efficiency as the proportion of eye movements that are directed to locations that can be easily ascertained to provide new information. In the office example, some surfaces will be empty, and some cluttered with books and papers. If your keys were in the middle of an empty surface, you would already know where they were; no new information would be gained by looking directly at these locations. An efficient searcher would instead direct their eyes to the cluttered regions, where central vision is needed. Our recent studies using this metric to define efficiency have found a surprisingly large range of individual strategies, with some people being highly efficient, some random, and some highly inefficient. These differences suggest that rather than asking "is search optimal or random?" we should be asking for whom, and in what circumstances, search is optimal or random. This is the aim of the current proposal.

Much is already known about how visual information guides attention during search. Far less is known about search strategy, which contributes far more variance to performance measures. Our key hypothesis is that individual differences in strategy can be explained, at least in part, by differences in experience with the visual content and configuration, even though (in our experiments at least) these have no bearing on what the optimal eye movements are or the difficulty of implementing an efficient strategy. To assess this hypothesis, we systematically measure the effect on search efficiency of visual content, layout of the search array, individual motivation, learning, and prior expertise.

Understanding strategy is fundamental to building a complete model of visual search. The results have implications for understanding the role of experience in shaping strategy that could have relevance beyond the context of visual search. The results can also be useful in designing environments that promote more efficient search, and developing training programs that can lead to faster and more accurate detection of targets.

The research is valuable to academics interested in modelling the visual, attentional, motor and decision processes and how these work together in visual search. Our results will account for a large source of variance and move this field forward substantially. The results can also be generalized to inform our understanding of human decision-making and strategic thinking, and thus will be of importance to researchers in this field as well. We will reach this audience through a wide range of conferences and symposia and publications, described in more detail in the section on academic beneficiaries.

Our key aim is to understand the visual and individual factors that contribute to search efficiency, and their interaction. Understanding how to improve search efficiency has obvious relevance to real-world situations in which fast and accurate visual search carries high stakes (security, search and rescue, and healthcare are some examples). The recruitment of airport security screeners to one of our experiments establishes a direct relationship with this industry, and we plan to host a knowledge exchange event where we invite these and other potential stakeholders to hear about the results of our work.

Our research in this area has already garnered a great deal of public interest. Evidently, spending too much time looking for lost objects is a situation that resonates for many people. Descriptions of our research on search efficiency have appeared in The Independent, New York Magazine, The New York Times, and The International Business Times, among many other newspapers and magazines. We will continue to engage with the media through journalists, but also by appearing at public engagement events, as described in the Impacts section.

The final impact of our project is educational. We have consulted closely with the postdoctoral researcher in devising both a programme of research, as well as flexible working schedule, that will allow her to thrive as a very promising early career researcher with substantial family responsibilities that might otherwise limit her career. We also provide research assistants with training, experience, and a multi-site network of support and management that will develop both their technical skills and their enthusiasm for basic research.