Feedback requirements for automatic speech recognition in the process control room

Automatic Speech Recognition (ASR) has great potential for use in control room systems; to date, there has been little research into the human factors issues this raises. For example, careful consideration needs to be given to the provision of adequate feedback to the user. We concentrate on the two main types of visual feedback: textual and symbolic. Two studies reported here show that little difference exists between them in user performance on a task requiring spoken control of a process. However, the results demonstrate a significant reduction in learning time when textual and symbolic feedback are combined. We defined the correction of device misrecognitions as a verbal decision task, for which Study 1 shows that textual feedback is most appropriate. However, Study 2 shows that textual feedback is more likely to be misunderstood than either symbols or a combination of text and symbols. A combination of both text and symbols is proposed as the most efficient form of feedback for the use of ASR in control room systems.