A longitudinal study of the effects of ecological interface design on skill acquisition

Results from evaluations of interface design concepts conducted over short durations may not generalize to longer time spans. In an attempt to address this issue, this paper presents a longitudinal study of the effect of interface design on skill acquisition in which participants' quasi-daily performance was observed over an unprecedented period of six months. The research was conducted in the context of DURESS II, a real-time, interactive thermal-hydraulic process control simulation that was designed to be representative of industrial systems. The performance of two interfaces was compared, one containing physical and functional (P+F) system representations based on the principles of the ecological interface design framework, and a more traditional interface based solely on a physical (P) representation. Participants were required to perform several control tasks, including start-up, tuning, shutdown, and fault management. The results indicate that the P interface led to significantly less-consistent performance than did the P+F interface; with the former, participants occasionally took up to 2 times longer to complete the required tasks, even after 5.5 months of daily practice. There was very little difference in average performance between the two groups. These results have important implications for designing interfaces that lead to efficient performance under normal operating conditions.