The sensory match effect in recognition memory refers to the finding that recognition is better when the sensory form in which an item is tested is the same as that in which it was studied. This paper examines the basis for the sensory match effect by manipulating whether a studied fragmented picture is tested with the same or a complementary set of fragments in a recognition memory test (Experiment 1) and in a fragment-identification test (Experiment 2). Assuming that fragment identification is a direct measure of perceptual fluency, we expected identical patterns of results across the two tests if perceptual fluency accounted for the sensory match effect in recognition memory. Instead, recognition memory showed a robust overall sensory match effect (the same fragmented image was recognized better than the complementary image), whereas fragment identification showed no overall sensory match effect (the same fragmented image was identified no better than the complementary fragmented image). Experiments 3 and 4 combined the two responses and showed that the basis for the sensory match effect in recognition memory was a subject's ability to recognize the matching fragments in the absence of conceptual information (when the test stimulus could not be identified), supporting the idea that the episodic trace of the sensory code is responsible for the sensory match effect in recognition memory. Experiment 5 demonstrated that subjects are able to use this sensory code as the sole basis for recognition memory.Dual-process models of recognition memory (Atkinson & Juola, 1973;Mandler, 1980) posit two bases for recognition memory. One process is a rapid familiarity judgment that is often assumed to rely on perceptual fluency Johnston, Hawley, & Elliott, 1991). The second process is a slower recall-like search (Atkinson & Juola, 1974;Humphreys & Bain, 1983;Mandler, 1980).The purpose ofthe present study was to examine the role ofperceptual fluency, a central component of many dualprocess models, in accounting for the sensory match effect in recognition memory. Perceptual fluency is the increase in ease or speed of perception conferred on an item by its prior presentation. Jacoby and Dallas (1981) proposed that one basis on which subjects could make a recognition memory decision was relative perceptual fluency, or the degree to which a previously experienced item can be more readily perceived than a new item. They supported this position by showing that certain variables, such as number and spacing of repetitions, had equivalent effects on both recognition memory and perceptual identification. Perceptual fluency is assumed to be useful in recognition memory because it indicates whether an item was previously presented, with previously presented items being more fluent. One of the central predictions of any model relying on perceptual fluency is that recognition memory performance will improve when the sensory characteristics of study and test stimuli are more similar. Matching sensory characteristics should enhance perceptua...