Chunk Limits and Length Limits in Immediate Recall: A Reconciliation.

Abstract

Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., N. Cowan, Z. Chen,& J. N. Rouder, 2004; E. Tulving & J. E. Patkau, 1962), other research has suggested that it is limited by the length of the material to be recalled (e.g., A. D. Baddeley, N. Thomson, & M. Buchanan, 1975). The authors investigated this question by teaching new paired associations between words to create 2-word chunks. The results suggest that both chunk capacity limits and length limits come into play. For the free recall of 12-word lists, 6 pre-learned pairs could be recalled about as well as 6 pre-exposed singletons, suggesting a chunk limit. However, for the serially ordered recall of 8-word lists, 4 pre-learned pairs could be recalled about as well as 8 pre-exposed singletons, suggesting a length limit. Other conditions yielded intermediate results suggesting that sometimes both limits may operate together.

What limits working memory capacity?

“…This pattern (finding A1a in Table 2) has been observed consistently with both verbal materials (Chen & Cowan, 2005;Service, 1998) and visual materials (Alvarez & Cavanagh, 2004;Hardman & Cowan, 2015), for different forms of complexity.…”

Improving patient recall of information: Harnessing the power of structure

“…It seems likely that the better recall of students in the structured condition can be attributed to ''chunking'': the ability to form highlevel clusters of information from low-level individual elements [38][39][40]. The concept of a ''chunk'' referring to a pattern of other symbols has been studied as a model of memory organization.…”

The effect of morphological complexity on short-term memory capacity

“…Two different types of verbal STM limitations seem to appear when reviewing the literature of immediate recall (e.g., Chen-Cowan 2005): a phonological limitation on the one hand a limitation in terms of chunks on the other. We will start presenting the latter one.…”

“…Although Miller's (1956) famous paper set STM limits in terms of chunks, only few studies (e.g., Johnson 1969;Slak 1970;Tulving-Patkau 1962;Zhang-Simon 1985) have investigated verbal limitations in terms of chunks, mainly because of methodological issues as put forward by Chen-Cowan (2005; see also Cowan et al 2004). The major problem (see also for this concern , Cowan 2001; is that it is difficult to know if a participant has encoded in STM different elements as different elements or as one element by chunking the information together.…”

“…In fact, unlike the number of chunks, which seems to be constant (see the constant-capacity hypothesis, Cowan et al 2004)-even when knowledge grows (e.g., Gobet 1998;Lane et al 2001;Gobet-Simon 2000)-and determined by attentional resources (for a review, see Cowan 2005), the size of chunks seems to be determined by one's LTM knowledge, therefore chunks can become larger with practice (Chen-Cowan 2005;Cowan et al 2004) and expertise (e.g., Chase-Simon 1973;Gobet-Simon 1996a;b), increasing the size of STM capacity.…”