Short-term order and item retention

Abstract

This paper evaluates two hypotheses: (a) that transposition errors made in the recall of letter strings occur as a by-product of acoustic confusion errors and do not represent the loss of order information, and (b) that order and item information are independently retained in short-term memory. An experiment was conducted in which four-consonant strings containing exactly zero or two acoustically confusable items were recalled in order after retention intervals of 3, 8, or 18 intervening digits, all characters being successively presented at a rate of 400 msec per item and read aloud by the subject. An analysis of errors in relation to intra- and extrastimulus sources of acoustic confusion, retention interval, and serial position produced results that refute hypothesis (a) and support hypothesis (b). The implications of the present results for an adequate theory of the short-term retention of ordered strings are indicated.