Effects of format complexity on user performance and facial electromyographic activity: I

摘要

Twenty males and females reporting experience with either a word processing or editing package were paid as volunteers to evaluate a 16-row database record that was presented 256 times successively on a video display terminal (VDT) screen. Each evaluation required a decision about whether the datum adjacent to a designated label field was identical to or different from a separately displayed “target” data item. The database record had four configurations (i.e., formats), which differed in terms of bit-level complexity, Decision times (i.e., latencies) were assessed in a repeated-measures experimental design, and concurrently, electromyographic (EMG) activity was recorded for the masseter (jaw) and corrugator supercilii (eyebrow) muscles. The results showed that decision times differed among the four formats, but bit-level complexity was found to be unrelated to decision times. Local density of information, however, was highest for the format showing the slowest decision time. Masseter EMG activity did not change reliably over a resting baseline, and it was not differentially affected by format complexity. Corrugator supercilii EMG activity was reliably greater during task performance than during a resting baseline, but it was not differentially affected by format complexity. Although different configurations of information have been known to affect user response time and task performance can evoke facial EMG activity, the available data do not support the conclusion that bit-level complexity of a database record displayed on a VDT screen is related to user performance or facial EMG activity.