In-vehicle electronics systems are generally known to pose a distraction risk to drivers and machine operators. Distraction effects could be more severe for heavy machine operators since these vehicles have minimal margins for error. Designers of in-vehicle systems should consider the interface design to minimize distraction. This study examined whether interface consistency could reduce workload in a multitasking situation. We know from previous work that interface consistency showed positive effects on performance only when the overall level of cognitive load in the task was high. Another goal of the current study was to elaborate on this finding by examining how interface consistency affected performance in a cognitively demanding dual task situation. In the present study, the group using the inconsistent interface performed significantly worse only during the dual task portion of the study. Results support the notion that interface consistency has a significant effect only when task complexity is sufficiently high. We discuss implications of this finding along with areas for future research. (Author/publisher)
Abstract