High-frequency words are recalled better than are low-frequency words, but low-frequency words produce higher hit rates in a recognition test than do high·frequency words. Two experiments provided new data on the phenomenon and also evidence relevant to the dual process model of recognition, which postulates that recognition judgments are a function of increments in item familiarity and of item retrievability. First, recall and recognition by subjects who initially performed a single lexical decision task were compared with those of subjects who also gave definitions of high-, low-, and very low-frequency target words. In the second experiment, subjects initially performed either a semantic, elaborative task or an integrative task that focused attention on the physical, perceptual features of the same words. Both experiments showed that extensive elaborative processing results in higher recall and hit rates but lower false alarm rates, whereas word frequency has a monotonic, linear effect on recall and false alarm rates, but a paradoxical, curvilinear effect on hit rates. Elaboration is apparently more effective when the potential availability of meaningful connections with other structures is greater (as for high-frequency words). The results are consistent with the dual process model.A major challenge to any theory of recognition of prior occurrences is the word-frequency effect. What is challenging is the paradoxical finding that highfrequency words are recalled better than low-frequency words but in episodic recognition, hit rates for lowfrequency words are higher than those for high-frequency words. The earliest study to report the word-frequency effect in recognition appears to be that of Gorman (1961), which was later generalized by Schulman (1967). It should be noted, though, that the paradoxical reversal is not simply a function of some uniqueness of low-familiarity words or of the testing procedure. Glanzer and Bowles (1976), for example, have shown that false alarms demonstrate the dominance of highfrequency words; they are higher for high-than for lowfrequency words.The present paper is concerned with providing more evidence for the generality of the phenomenon across different kinds of processing conditions, and also with relating these to the dual process model of recognition (see Mandler, 1979Mandler, , 1980Mandler, , 1981.The dual process model states that the recognition of prior occurrence is the result of two additive and separate processes: familiarity and retrievability. We have assumed that the familiarity of an event is determined by the integration, perceptual distinctiveness, and internal structure of that event. Familiarity is affected by the frequency of exposure of the eventThe research reported here and the preparation of this report were supported by National Science Foundation Grant BNS 79-15336. George Goodman is now at BellLaboratories, Piscataway, New Jersey. Requests for reprints should be sent to George Mandler, Center for Human Information Processing, C-Q09, University of Ca...