CODING STRATEGIES IN SHORT‐TERM MEMORY

Research studies on the process of remembering, which is a complex characteristic of human beings, involve investigations of how we perceive, learn, store, and retrieve the large amount of information that we encounter in our environment each day. Psychologists studying memory for sequences of items are investigating one aspect of a human’s ability to remember information. Researchers studying short-term memory in the laboratory have used an information-processing approach and have modeled human memory processes using an analogy of a complex computer. Many assumptions are made about how humans remember when using this informationprocessing language to describe memorial processes for the somewhat “simplified” laboratory memory task. The focus of this paper is a retrospective review of the coding strategies used by subjects in remembering. Most of these coding processes or strategies are inferred from studies involving sequences of items presented in a serial order either visually (by slides, for example) or auditorily (as by taperecorded voice). In these tasks we are attempting to study human ability to organize relatively random sequences of digits, letters, words, shapes, and the like. In investigating coding processes, we are trying to understand the operations the subject performs on the items presented in transforming those items for recall. Several authors have made a distinction between the reduction and elaboration of items for coding processes.’ A recent summary of the various types of elaboration and reduction coding can be found in Herriot* or in the paper published by Craik and Lockharts in 1972. Elaboration coding for an individual item is assumed to be used by the subject to provide enough unique features to successfully discriminate that item from other items. Items can be elaborated on by the codes that a subject extracts or adds at the time of presentation of items, during the storage time required, or during the act of retrieving the item. Reductive coding, on the other hand, may be exemplified by a transformation of each three binary numbers into a six-unit octal code during the presentation of 18 binary digits. Experimenters investigating coding processes that a subject uses for a particular sequence of items also recognize that subjects can do more than one type of coding on items if given adequate time and instructions to do so. In studies of coding, experimental procedures include manipulation of both the characteristics of the sequences of items and the instructions about how to reproduce the items given. If the items are to be recalled in the exact order presented, we are studying “serial” recall processes involved in retrieving both order and item information from short-term memory