Supporting operator problem solving through ecological interface design

This paper describes two experiments evaluating ecological interface design (EID), a novel theoretical framework for the design of interfaces for complex human-machine systems. According to EID, to properly support operator problem solving activities, an interface should display both the physical and functional properties of the work domain in the form of a multilevel representation based on the abstraction hierarchy. To evaluate this claim, two interfaces for a thermal-hydraulic process simulation were developed, one based on a traditional format containing only physical information (P) and another based on EID which also contained information about higher-order functional variables (P+F). The findings of Experiment 1 are consistent with the claim that an interface based on an abstraction hierarchy representation can provide more support for problem solving than an interface based on physical variables alone, thereby providing some initial support for the EID framework. There was also some evidence to indicate that theoretical expertise is required to enjoy the full benefits of the P+F interface. The findings of Experiment 2 indicate that subjects who exhibited effective diagnosis performance using the P+F interface tended to start their search at a high level of abstraction and gradually work their way down to more detailed levels, as predicted. Furthermore, previous experience with the DURESS system was found to be the most reliable background variable that predicted performance