An information processing model of pharmacists' cognition: Research on typicality biases in performance.

Abstract

An information processing model was developed to describe how information used by pharmacists in providing pharmacy services is processed. The process is hypothesized to be sequential and to consist of perception, recognition, judgment, decision making and response control components which continuously interact and are influenced by memory, particularly long term memory. Information in long term memory was hypothesized to be organized according to the perceived typicality of the stimulus. A laboratory methodology using a microcomputer was developed to test the effect of typicality on three of the process components, recognition, judgment and decision making. Three groups of ten subjects were tested, practicing pharmacists, pharmacy technicians and fourth year PharmD students. For the recognition task, subjects were shown a drug name on the computer screen then asked to indicate which of two drug names, one typical and one atypical, was shown. Pharmacists' responses were most likely to be biased toward the typical drug, technicians' responses were less likely to be biased and students' responses were least likely to be biased. For the judgment task, subjects were shown a drug name and a brief description of a typical or atypical patient; subjects were asked to indicate whether the drug was likely to be appropriate therapy for the patient. Pharmacists' responses were most likely to be biased by the perceived typicality of the patient, technicians, less likely and students, least likely. The decision task was identical to the judgment task except subjects were asked to indicate whether they would dispense the prescription as written or whether they would contact the prescriber. Pharmacists' choices were most likely to be influenced by the perceived typicality of the patient, and technicians were less likely to be influenced by typicality. Students' responses appeared not to be influenced at all. When between groups comparisons were made on difference scores, only the comparison between pharmacists and students on the decision task was significant. No statistically significant differences were found on the reaction time dependent variable for any of the subject groups.