AN INTERFERENCE THEORY EXPLANATION OF RETENTION ERRORS

We have extended Cognitive Complexity Theory (CCT) (Kieras and Polson, 1985) to provide an explanation of why some production rules are rememberd and others are forgotten. This explanation is based on interference theory.Inconsistent user-interfaces force users to learn different operations to accomplish common user goals. Such inconsistent knowlege is represented as two or more rules with common conditions and different actions. Let A represent the common condition and C and D represent different actions. The rules can be described as A-B and A-C which conform to a classical interference paradigm.Sixty subjects were traine to perform seven utility tasks on a popular, stand-alone, menu-based word processor. Subjects were brought back one day after the training session for a retention test. The retention test involved retraining subjects on the same set of utility tasks.Production rule models were written for all tasks. Each rule represents a step in one of the seven tasks. The rules were classified as A-B, A-C, or C-D rules. C-D rules are rules with a unique condition and action. The rule that appeared more frequently was predicted to interfere with the retention of the less frequent version of the rule (Postman & Underwood, 1973).Each step can be associated with a rule, and the number of errors were tobulated for each rule type. The overall probability of an error was .076. The observed probability of an error was .56 for the four low-frequency A-C rules. Over half the errors observed in this study were made or these four steps. The probability of an error on a low-frequency C-D rule was .005.