The frequency effect in short-term serial recall is influenced by the composition of lists. In pure lists, a robust advantage in the recall of high-frequency (HF) words is observed, yet in alternating mixed lists, HF and lowfrequency (LF) words are recalled equally well. It has been argued that the preexisting associations between all list items determine a single, global level of supportive activation that assists item recall. Preexisting associations between items are assumed to be a function of language cooccurrence; HF-HF associations are high, LF-LF associations are low, and mixed associations are intermediate in activation strength. This account, however, is based on results when alternating lists with equal numbers of HF and LF words were used. It is possible that directional association between adjacent list items is responsible for the recall patterns reported. In the present experiment, the recall of three forms of mixed lists-those with equal numbers of HF and LF items and pure lists-was examined to test the extent to which item-to-item associations are present in serial recall. Furthermore, conditional probabilities were used to examine more closely the evidence for a contribution, since correct-in-position scoring may mask recall that is dependent on the recall of prior items. The results suggest that an item-to-item effect is clearly present for early but not late list items, and they implicate an additional factor, perhaps the availability of resources at output, in the recall of late list items.Keywords Short term memory . Language production . RecallIn the context of immediate serial recall, the frequency effect is complex and difficult to explain in straightforward terms Early explanations of the frequency effect in serial recall, motivated by the results from experiments using pure lists, focused on item-specific differences between HF and LF words, consistent with the prevailing explanation of verbal short-term memory (STM) phenomena. For example, the phonological loop (Baddeley & Hitch, 1974) was characterized as a serially ordered, speech-based system that was responsible for performance on memory span and serial recall tasks (Baddeley, 1986). It comprised a phonological shortterm store (STS) that retained the short-term traces of items and a subvocal rehearsal mechanism. Traces in the STS were subject to passive decay and consequent degradation unless refreshed by rehearsal in the loop. Wright (1979) demonstrated articulation rate differences between HF and LF words; HF items of the same length are articulated faster than LF words. Accordingly, the frequency effect will manifest from rehearsal rate differences between HF and LF words, since greater rehearsal efficiency leads to superior retention of the shortterm traces on which recall is reliant.