Sequential revision of belief: an application to complex decision making situations

This research addresses the process of sequential revision of beliefs or judgments in complex situations. The task domain, military command and control, provides decision makers with opportunities to revise their tactical judgments as streams of information flow in for their consideration. A contrast-inertia model is proposed that describes subject´s sequential revision of beliefs exhibited by subjects and a resulting order-effect that is observed when subjects attempt to integrate pieces of confirming and disconfirming evidence. Two experiments were conducted to test the predictions of the contrast-inertia model and to investigate various aspects of the order effect. The experiments manipulated the initial starting position or anchor against which subjects contrast new evidence to revise their beliefs. Results form both experiments showed strong recency and order effects when subjects integrated inconsistent pieces of evidence sequentially, regardless of the initial anchor. Moreover, the contrast-inertia model fit the experimental data very well and confirmed the basic assumptions predicting an order effect