Human Factors in Reliability and the Psychology of Communications

By developing ideas which attempt to identify and explain some of the more commonly occurring psychological mechanisms of human error this article aims to provide a background of understanding which will be helpful to the systems analyst in his task of predictive reliability assessment. A simple hypothetical model of the mind is described from which human error mechanisms are explained. An underlying theme is that of communication. Accepting that accidents develop when there arises a persisting misalignment between the true state of a system and the operator's perception of that state, the article examines the processes by which this updating takes place. An experimental technique “communications analysis” is presented as a possible analyst‐aid for the prediction of error‐event sequences. The technique is illustrated by application to a nineteenth‐century railway signalling system.