Abstract

Four Ss were run in a visual span of apprehension experiment to determine whether second choices made following incorrect first responses are at the chance level, as implied by various high threshold models proposed for this situation. The relationships between response biases on first and second choices, and between first choice biases on trials with two or three possible responses, were also examined in terms of Luce's choice theory. The results were: second choice performance in this task appears to be determined by response bias alone, i.e., second choices were at the chance level; first and second choice response biases were not related according to Luce's choice axiom; and the choice axiom predicted with reasonable accuracy the relationships between first choice response biases corresponding to trials with different numbers of possible response alternatives. © 1967 Psychonomic Society, Inc.