Multi-Modal Interfaces in Supervisory Control

The resource metaphor emphasizes the divisibility of attention. When performing any task, different mental operations must be carried out, each of which requires some degree of the operator's limited processing resources. In a supervisory control environment, visual processing resources are in high demand to monitor the typically large number of displays, as are manual resources to perform such tasks as adjusting dials, entering data into logbooks, and typing on keyboards. A need exists to develop multi-modal interfaces to take advantage of processing resources which are not currently used to advantage. Speech input is proposed as a means of facilitating operator interaction. An experiment incorporating speech input into a simulated control room environment compared the performance of operators using voice-augmented and keyboard inputs. It was found that speech input actually hindered the operator's control performance.