Citation

Pretorius LL, Hanekom JJ. Hum. Factors 2006; 48(4): 774-784.

Affiliation

Department Electrical, Electronic and Computer Engineering, University of Pretoria, Lynnwood Road, 0002, South Africa. linda@postino.up.ac.za

Copyright

(Copyright © 2006, Human Factors and Ergonomics Society, Publisher SAGE Publishing)

DOI

unavailable

PMID

17240724

Abstract

OBJECTIVE: The objective was to develop a time-efficient method, based on an adaptive psychophysical technique, to reliably determine the boundary of the conspicuity area. Because full-field mapping is time consuming, estimating the boundary from only a limited amount of target presentations is attractive. BACKGROUND: Detectability of visual targets can be evaluated by measuring their associated conspicuity areas. Earlier literature reported elliptical conspicuity areas, but later research that found shape irregularities brought into question the validity of using techniques based on this assumption to approach the area's boundary. METHOD: Eight participants were required to view briefly presented target-background combinations, with successive target positions depending on preceding observer responses. RESULTS: Nonlinear least squares curve fitting showed conspicuity areas to be elliptical. Results from response time (RT) studies supported the finding, showing that slopes of RT versus eccentricity functions were markedly steeper at positions outside the conspicuity area than at those within. CONCLUSION: It is proposed that the developed method provides a time-efficient and accurate means to measure the conspicuity area. APPLICATION: The findings are applicable to industries in which target detectability needs to be assessed in order to either reduce (e.g., for camouflage) or enhance detectability (e.g., road safety).

Language: en