Assessing visual search performance differences between Transportation Security Administration Officers and nonprofessional visual searchers

Abstract

Some visual searches depend upon accuracy (e.g., radiology, airport security screening), and it is important for both theoretical and applied reasons to understand what factors best predict performance. The current study administered a visual search task to both professional (Transportation Security Administration Officers) and nonprofessional (members of Duke University) searchers to examine group differences in which factors predict accuracy. Search speed—time taken to terminate search—was the primary predictor for nonprofessional searchers (accounting for 59% of their accuracy variability) and for the least experienced professional searchers (37% of variability). In contrast, consistency—how similarly (in terms of search speed) an individual spent searching from trial to trial—was the primary predictor for the most experienced professional visual searchers (39% of variability). These results inform cognitive theory by illuminating factors that differentially affect search performance between participants, and real-world issues by identifying search behaviours (consistency in particular) important to experienced professional searchers.

Keywords:

• Consistency
• Experience
• Performance
• Visual search

Acknowledgments

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 RDU airport. 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 Ricky Green and undergraduate research assistants for assistance with data collection at Duke University. This work was partially supported by the Army Research Office (No. 54528LS) and partially through a subcontract with the Institute for Homeland Security Solutions, a research consortium sponsored by the Human Factors Division in the Department of Homeland Security (DHS). This material is based upon work supported by the DHS under Contract No. 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 US Government. The study is approved for public release. MSC is now at the Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, USA.

Notes

¹Ages are represented as approximations since TSA Officers reported their age via ranges in a questionnaire (e.g., between 18 and 25 years old).

²As noted previously, the consistency measure (Equation 1) incorporates the standard deviation of response times for each set size for each participant. Although this is potentially susceptible to differences in trial counts, the differences were minimal. Each of the values reported in this section were also calculated with standard error used in place of standard deviation in Equation 1, which reduces the impact of uneven trial counts, and the outcomes were the same.