Different predictors of multiple-target search accuracy between nonprofessional and professional visual searchers

Abstract

Visual search, locating target items among distractors, underlies daily activities ranging from critical tasks (e.g., looking for dangerous objects during security screening) to commonplace ones (e.g., finding your friends in a crowded bar). Both professional and nonprofessional individuals conduct visual searches, and the present investigation is aimed at understanding how they perform similarly and differently. We administered a multiple-target visual search task to both professional (airport security officers) and nonprofessional participants (members of the Duke University community) to determine how search abilities differ between these populations and what factors might predict accuracy. There were minimal overall accuracy differences, although the professionals were generally slower to respond. However, the factors that predicted accuracy varied drastically between groups; variability in search consistency—how similarly an individual searched from trial to trial in terms of speed—best explained accuracy for professional searchers (more consistent professionals were more accurate), whereas search speed—how long an individual took to complete a search when no targets were present—best explained accuracy for nonprofessional searchers (slower nonprofessionals were more accurate). These findings suggest that professional searchers may utilize different search strategies from those of nonprofessionals, and that search consistency, in particular, may provide a valuable tool for enhancing professional search accuracy.

Keywords:

• Visual search
• Individual differences
• Expertise
• Multiple targets

We thank Michael Zunk, Hung Nguyen, Bob Kingan, Kellis Turner, Ken Macdonald, Richard Menard, and Everett Vaughn for making it possible to conduct research at Raleigh-Durham International airport (RDU). We especially thank Dave Evans and Stuart Campbell for their extraordinary efforts to support the research at RDU. We also thank Stephen Adamo and Emma Wu Dowd for helpful comments, and Elise Darling and undergraduate research assistants for assistance with data collection at Duke University.

This work was partially supported by the Army Research Office [number 54528LS] and partially through a subcontract with the Institute for Homeland Security Solutions, a research consortium sponsored by the Resilient Systems Division in the Department of Homeland Security (DHS). This material is based upon work supported by the DHS [contract number HSHQDC-08-C-00100]. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the official policy or position of DHS or of the U.S. Government. The study is approved for public release.

Notes

¹ Because TSA officers participated as part of their regular workday, they were given the option of allowing their data to be used only for TSA purposes or for both TSA and research purposes. There were an additional 9 professional participants who were tested, but did not provide consent for their data to be used for research. As such, data from these individuals are not included in the analyses.

²Professional experience is constrained by the creation of the TSA on November 19, 2001.