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

Lead Research Organisation: University of Aberdeen
Department Name: Psychology

Abstract

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.

Planned Impact

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.

Publications

10 25 50
 
Description In these first five months of the grant period, we completed data collection for two experiments measuring the effect of financial rewards and deadlines on visual search strategies (described as Set 2.1 of the case for support). The aim was to address the concern that sub-optimal strategies and individual differences we previously observed were, at least in part, a consequence of low motivation or a failure to prioritize search speed. The results ruled out these explanations. In one experiment, all the participants performed the first half of the experiment with a simple instruction to be fast and accurate (matching instructions used in previous experiments). In the second half of the experiment, some participants were instructed to try to find the target faster than they did in the first half, and were told they would be given an additional £5 reward if they could respond 10% faster, and an additional £10 if they could respond 20% faster (while maintaining at least the same level of accuracy). The participants who had additional incentive to be fast did not exhibit better search strategies than those who simply performed the task over two blocks, with a flat payment for compensation. We found a similar result in a second experiment in which we shortened the duration of the search array to 2 seconds: participants did not become more efficient when they had less time available for searching. An observation across both these experiments, however, was a consistent improvement in strategy over time, with fewer "wasted" fixations on un-informative regions of the search array in the second block of the experiment relative to the first.
Exploitation Route It is very early in this grant (month 5 of 36), and strong conclusions about practical applications would be premature. That said, the results suggest a slow increase in search efficiency with experience; we failed to find any "shortcut" to more efficient search through incentives or emphasis on speed. This could have training implications in industries that require efficient information-sampling (e.g. aviation, security, healthcare).
Sectors Aerospace, Defence and Marine,Healthcare,Security and Diplomacy,Transport

 
Description Does pre-crastination explain why some observers are sub-optimal in a visual search task? 
Organisation University of California, Riverside
Country United States 
Sector Academic/University 
PI Contribution In this collaborative project, we are collecting a large dataset (N=200) in Aberdeen and Essex. The ongoing experiment replicates our visual search experiment along with a range of other tasks, including one task developed by the collaborators, to establish contributions to individual differences in search strategies. We conducted an initial pilot study (N=30) in Aberdeen to verify the methods are appropriate, to estimate the required sample size, and to develop the analysis approach. Participants are recruited and run in Aberdeen (N=80 to date) and will also participate in Essex (to commence soon). The PDRF has supervised data collection. The Co-I, PDRF and PI on this ESRC grant took the lead in writing a pre-registered report and submitting it, and in responding to editor and reviewer comments on the submission. Financial compensation for participants has been provided by the grant funds.
Collaborator Contribution Collaboration partners (David Rosenbaum and Kyle Sauerberger in California, and Tom Zentall in Kentucky) consulted on the design of the tasks, and made comments on the pre-registered report and responses to editor and reviewers comments. They are hosting the software collecting questionnaire and demographic data, and regularly compiling the results and uploading them to a shared github repository.
Impact 1. A pre-registered report has undergone peer review and received stage-1 acceptance at the journal Royal Society Open Science. The title of the report is: "Does pre-crastination explain why some observers are sub-optimal in a visual search task?" and the authors are Alasdair Clarke, Kyle Sauerberger, Anna Nowakowska, David A. Rosenbaum, Tom Zentall, and Amelia Hunt. We have agreed with the journal to complete data collection within 12 months and submit the stage-2 manuscript by January 2021. 2. Based on the pre-registered hypothesis and preliminary results, we submitted an abstract to present at the Vision Sciences Society conference (Florida, USA, May 2020) entitled: Optimal Visual Search, Individual Differences and Pre-Crastination. It was accepted and will be presented by the co-investigator, and the authors are the same as those listed above. 3. We have collected additional exploratory data in the same experiment, and based on these data we have submitted an abstract to the Scottish Vision Group meeting (Dunkeld, UK, April 2020) entitled: "Can we account for individual differences in visual search?". The authors are the same as those listed above.
Start Year 2019
 
Description Does pre-crastination explain why some observers are sub-optimal in a visual search task? 
Organisation University of Kentucky
Country United States 
Sector Academic/University 
PI Contribution In this collaborative project, we are collecting a large dataset (N=200) in Aberdeen and Essex. The ongoing experiment replicates our visual search experiment along with a range of other tasks, including one task developed by the collaborators, to establish contributions to individual differences in search strategies. We conducted an initial pilot study (N=30) in Aberdeen to verify the methods are appropriate, to estimate the required sample size, and to develop the analysis approach. Participants are recruited and run in Aberdeen (N=80 to date) and will also participate in Essex (to commence soon). The PDRF has supervised data collection. The Co-I, PDRF and PI on this ESRC grant took the lead in writing a pre-registered report and submitting it, and in responding to editor and reviewer comments on the submission. Financial compensation for participants has been provided by the grant funds.
Collaborator Contribution Collaboration partners (David Rosenbaum and Kyle Sauerberger in California, and Tom Zentall in Kentucky) consulted on the design of the tasks, and made comments on the pre-registered report and responses to editor and reviewers comments. They are hosting the software collecting questionnaire and demographic data, and regularly compiling the results and uploading them to a shared github repository.
Impact 1. A pre-registered report has undergone peer review and received stage-1 acceptance at the journal Royal Society Open Science. The title of the report is: "Does pre-crastination explain why some observers are sub-optimal in a visual search task?" and the authors are Alasdair Clarke, Kyle Sauerberger, Anna Nowakowska, David A. Rosenbaum, Tom Zentall, and Amelia Hunt. We have agreed with the journal to complete data collection within 12 months and submit the stage-2 manuscript by January 2021. 2. Based on the pre-registered hypothesis and preliminary results, we submitted an abstract to present at the Vision Sciences Society conference (Florida, USA, May 2020) entitled: Optimal Visual Search, Individual Differences and Pre-Crastination. It was accepted and will be presented by the co-investigator, and the authors are the same as those listed above. 3. We have collected additional exploratory data in the same experiment, and based on these data we have submitted an abstract to the Scottish Vision Group meeting (Dunkeld, UK, April 2020) entitled: "Can we account for individual differences in visual search?". The authors are the same as those listed above.
Start Year 2019