Assessing Information Integration Processes Using Between- or Within-Subjects Designs: Some More Evidence

Abstract

Within-subject designs (WSDs) remain unappreciated in psychology although many experimental tactics can reduce or eliminate the demand and order effects that WSDs tend to create. Comparative studies conducted in the Information Integration Theory (IIT) framework have shown that patterns of results observed using WSDs can largely be replicated using between-subject designs (BSDs). In order to add evidence to these findings, three additional studies were conducted in order to complement data obtained in previous studies. One of these studies was about health risk perception and tested the possibility to find evidence for a disjunctive rule of information integration using a BSD. The other two studies focused on the valuation process of IIT. The new findings regarding the disjunctive rule added support to the view that equivalent results can be obtained either with a highly economical repeated-measures design or with a much costlier independent factorial group arrangement. However, when the focus was on the valuation process and not on the integration process, ratings obtained in the BSD condition seemed to be restricted to a limited range of values by comparison with ratings obtained in the WSD condition. An explanation in terms of context effect is offered.