Deferred decision in human signal detection: A preliminary experiment

In the detection task characterized by deferred decision, the observer is allowed to determine how many observations he will make before deciding whether or not a signal is present, and he is called upon to balance the goals of maximizing accuracy and conserving time. The human observer appears capable of using the optimal process of cumulating sensory information over successive observations, but certain common training procedures lead him to use a less efficient process. Though he displays a consistent decision bias, his performance is also in good agreement with the optimal model of the process of terminating a sequence of observations.