A comprehensive review of the principal empirical findings in the study of choice reaction time is provided, with particular emphasis on effects due to types of preparation bias by the subject and their relation to errors. This is followed by a brief review of the chief types of model which have been proposed for choice reaction processes. The fast-guess model is focused on in detail, including a full explanation of the process of parameter estimation. Some experiments are reported which utilise the fast-guess model in an attempt to establish the locus of certain well-known findings. Finally, a scheme for a comprehensive stage model of choice reaction processes is suggested, which is developed with the aid of Sternberg's additive factor method. The scheme incorporates bypass features not normally included in such models, in an attempt to account for certain preparation effects described earlier
