An analysis of human error in skill task and visual recognition under auditory interruption

When a car driver communicates with someone using a hands-free telephone, he has to do three extra tasks besides driving; to listen to and to understand the person whom he is talking to, to think of the answer, and to talk. The paper describes a research experiment in which an environment consisting of three tasks on a computer screen is used to analyze quantitatively the mutual effect of these tasks. The first is a tracking task, which is a typical skill-based one. The second is to recognize the visual information that is indicated by four different media on a computer screen and to respond as soon as possible. The third is to listen to a conversation and answer a question about it. In this paper we have examined the effect of third task on the first and the second tasks. There was no effect on the performance of the tracking task. The time needed to respond after getting the information was affected a little by the third task. The number of instances of overlooking the visual information in the second task was significantly increased by the effect of the third task. This point might be one of the causes that result in a car accident.