The Effects of Format in Computer-Based Procedure Displays

Abstract

Two experiments were conducted to investigate display variables likely to influence the effectiveness of computer-based procedure displays. In Experiment 1, procedures were presented in three formats, Text, Extended-Text, and Flowchart. Text and Extended-Text are structured prose formats which differ in the spatial density of presentation. The Flowchart format differs from the Text format in both syntax and spatial representation. Subjects were required to use the procedures to diagnose a hypothetical system anomaly. The results indicate that performance was most accurate with the Flowchart format. Although overall completion times did not differ significantly across formats, the Flowchart format required significantly less time for step implementation. In Experiment 2, procedure window size was varied (6-line, 12-line, and 24-line) in addition to procedure format. In the six line window condition, Experiment 2 replicated the findings of Experiment 1. Procedures in the Flowchart format were completed with greater accuracy than procedures in either of the text formats. As predicted, completion times for Flowchart procedures decreased with increasing window size; however, accuracy of performance decreased substantially. Implications for the design of computer-based procedure displays are discussed.