Abstract
“Alphanumeric category effect” refers to the finding that letters and digits are identified more efficiently when they were presented among items from the opposite category (a between-category condition, BC) than among items from the same category (a within-category condition, WC). Two experiments in this article revealed that the category effect occurred when BC and WC condition were divided into blocks but did not occur when these were not divided. This means that the category effect is due to strategy of the subjects rather than to category relation between target and distractor.
