This paper presents a model of human information-purchasing behaviour in Bayesian decision task.
In this field, several models have been presented, particularly by EDWARDS. From the results of probability-estimation experiments, EDWARDS assumed that human underestimate the diagnostic value of information, and modified the optimal purchasing strategy of the decision task to describe the human behaviour.
WALLSTEN and others have reported data on this subject obtained through a series of experiments based on the suggestion by EDWARDS. Comparing the model and the experimental data, the author proposes a modification of the model in mathematical treatments and provides a new revised model.
Validity of this revised model is examined by comparing the model-behaviour and the experimental data reported by WALLSTEN and by others. It is also remarked by the author for human in the decision task to overestimate the diagnostic value of information. Finally, some implications of the revised model are mentioned.