A Taxonomic Analysis of Vigilance Performance

Task classification is introduced as a method for the evaluation of vigilance behaviour in different task situations. On the basis of an analysis of different vigilance tasks, several task “dimensions” of relevance to a taxonomy of vigilance tasks are identified. The perceptual speed and flexibility of closure ability categories, which may also be identified with signal discrimination type, are considered to comprise one of the major dimensions in the taxonomy. In the first study, two experiments are reported whose results indicate that these ability categories exert a significant influence on the determination of the consistency of performance between different vigilance tasks, and that individual differences in vigilance performance are not so much task specific as task-type specific. In the second study, it is demonstrated that a classification of the vigilance literature leads to an improved specification of the types of tasks in which reliable decrements in efficiency occur, in terms of a few dimensions of the vigilance task taxonomy. It is concluded that task classification enables the specification of task situations to which particular classes of performance are restricted, and the systematization of the research literature so that improved generalizations can be made in extrapolating data from one laboratory task to another and from laboratory to operational tasks.