This study explores the application of signal detection theory to the analysis of consumers’ product-locating behavior. Two research questions are addressed: (1) whether characteristics of the shopping environment, including external memory aids and store layout, affect signal-detection statistics and (2) whether the signal-detection statistics can be predicted from subjective measures of shopping motivation and product familiarity. The experiments are conducted in a virtual store. The results show that (1) the signal-detection statistics of sensitivity and response bias can be used to measure product-locating behavior; (2) external memory aids significantly affect sensitivity; and (3) signal-detection statistics are significantly associated with shopping motivation.