Specializing the operation of an explicit rule.

Abstract

The effect of practice on the operative form of a rule was investigated by giving subjects an easy, perfectly predictive classification rule, followed by training in applying that rule to a set of practice items. On a subsequent transfer test, the accuracy and speed of classifying new items was strongly affected by similarity to previously seen items, suggesting that the effect of practice was not simply to automatize the rule. The effect occurred with pictorial, easily integrated stimuli, but not with lists of verbally stated features. Subjects generally did not have insight into the role of previous items in their performance. This dependence on prior episodes may be frequent in ecologically common conditions and is of special interest when the categorization rule becomes uncertain, as when a rule has only heuristic value.When dealing with a newly learned rule, one is often aware of relying on previous episodes of applying the rule. The specific materials or problems to which the rule was originally applied seem to have some privilege, particularly when the rule initially seems quite abstract. Understanding a difficult rule, or at least understanding how to apply it, seems to occur in terms of previous concrete applications. This impression is corroborated by Ross in his interesting work on remindings in problem solving (Ross, 1984(Ross, , 1987(Ross, , 1989 Ross & Kennedy, 1990). He demonstrated that performance while learning a word processing program or learning to solve simple probability problems is influenced by specific analogies with previously encountered problems.But what happens to these prior episodes of problem solving when the rule is not difficult, or when one has had sufficient practice to make it no longer seem difficult? Introspectively, the prior examples seem to disappear from active processing, a suggestion reflected in a wide variety of theories in cognitive psychology. In this article we argue that under common conditions, prior episodes retain an important role in helping apply the rule to new material, well after clear awareness of the prior episodes has disappeared. We make an ecological argument for the conditions under which episode-based knowledge has continued value. Abstractive GeneralizationAn intuitively plausible view of the changes in processing that occur during practice with a rule is what we will refer to as abstractive generalization. With increasing practice, processing comes under the control of fast, general, and automatic procedures that concentrate solely on the relevant information given in the stimulus display. With practice, a rule that was explicitly known becomes automatized, consuming a decreasThis research was carried out with the support of the Natural Sciences and Engineering Research Council of Canada, through a graduate scholarship to Scott W. Allen and a grant to Lee R. Brooks.

Alternative strategies of categorization

“…Another such condition is that test objects be perceptually distinct, leading to a reduction in interference from other items during retrieval. Follow-up studies by Allen and Brooks (1991) and Regehr and Brooks (1993) support both of these predictions. When the test objects were made either less integrated or less distinctive, there was a decrease in the difference in errors between negative and positive matches-the litmus test for exemplar similarity.…”

“…A useful starting point is an experiment by Allen and Brooks (1991), which is worth describing in detail because it sets the stage for much of what follows. The subjects' task was to categorize imaginary animals into two categories, referred to as 'Builders' and 'Diggers.'…”

“…1. Examples of materials used by Allen and Brooks (1991). The top right cell illustrates a Positive Match because, not only are these animals Builders according to the rule, but they are also most similar to the studied Builders in the top left cell.…”

“…Indeed, further analysis by Allen and Brooks (1991) of just the Rule group showed that exemplar similarity was also involved. The logic of their analysis was as follows.…”

“…In the study by Allen and Brooks (1991), it seems obvious that the rule instructions induced in subjects a conscious intention to apply the given rule, but it is difficult to go beyond this rather abstract statement.…”