Evaluation of simulated automotive displays using a dual-task methodology
Mayer, David Louis, III
Laughery, Kenneth R., Sr.
Doctor of Philosophy
Modern automotive instrument panels are often equipped with numeric readout and digital bargraph displays instead of traditional analog displays. An informal survey of 1990 model cars revealed wide disparity in automotive displays. Three major classes of displays were in use: (1) traditional analog, (2) binary indicators, and (3) readout displays. The present work reports results from four experiments of display monitorability. Twelve computer-simulated displays were designed for evaluation by dual-task methodology. Subjects were required to maintain performance on a demanding tracking task while monitoring configurations of four-displays for "critical readings." Subjects' latencies to respond to such readings and their tracking error scores were collected. Experiment 1 examined displays in homogeneous clusters. Orientation, configuration and class were studied. Experiment 2 compared displays in heterogeneous configurations. Experiment 3 studied the addition of color to the displays to facilitate the detection of a critical reading. Static color (i.e., a "red zone") was added to the analog displays while dynamic color was added to the bargraph displays. Finally, Experiment 4 examined the effect of check-readable layouts for analog and bargraph displays. Older subjects were slower to respond to all displays and exhibited poorer tracking performance. They also had more variability than younger subjects on both of these measures. This result was likely due to age-related slowing rather than changes in cognitive processes. No class of displays studied emerged as superior, but the binary indicator (a modified warning lamp) generated the fastest responses. Although no evidence was found for effects of orientation, configuration or check-readability, support was found for color facilitation. Male subjects tended to respond faster when static color was present, and age-related facilitation was found for dynamic color. The addition of dynamic color to displays monitored by subjects in the middle and older age groups approximately compensated for age-related RT decrements. It is likely that displays which incorporate dynamic color elements will be most useful for presenting rate information as well as calling attention to off-normal readings. Pending further study, it is recommended that designers use new display technology with caution.