Year: 2009
Type: article
Abstract: 3URFHVVLQJ7LPH(YLGHQFHIRUD'HIDXOW,QWHUYHQWLRQLVW0RGHORI3UREDELOLW -XGJPHQWV (OOHQ*LOODUGHOOHQJLOODUG#SHGNXOHXYHQEH Centre for Instructional Psychology and Technology, Vesaliusstraat 2 B-3000 Leuven, Belgium :LP9DQ'RRUHQZLPYDQGRRUHQ#SHGNXOHXYHQEH Centre for Instructional Psychology and Technology, Vesaliusstraat 2 B-3000 Leuven, Belgium :DOWHU6FKDHNHQZDOWHUVFKDHNHQ#SV\NXOHXYHQEH Laboratory of Experimental Psychology, Tiensestraat 102 B-3000 Leuven, Belgium /LHYHQ9HUVFKDIIHOOLHYHQYHUVFKDIIHO#SHGNXOHXYHQEH Centre for Instructional Psychology and Technology, Vesaliusstraat 2 B-3000 Leuven, Belgium $EVWUDFW We report an experiment examining dual-process models of probability judgments. Participants had to judge which of two samples provided the best chances of picking a target. Often, participants based their judgment on a comparison of the absolute frequencies of the targets instead of on the ratios. The comparison of the absolute frequencies of the targets was either congruent with the comparison of the ratios (congruent condition), or not (incongruent condition). In this study, the proportion of incongruent (versus congruent) trials was manipulated. Accuracy rates and reaction times were recorded. Accuracy rates for incongruent items decreased but remained unchanged for congruent items when more congruent items were presented. The most striking reaction time result is that the RTs for correct responses to congruent items drastically increased when fewer such items were presented, whereas the RTs for correct and incorrect responses to incongruent items remained unchanged. This increase in RTs for correct responses to congruent items runs counter to the parallel-competitive model, but can in our opinion be reconciled with a default-interventionist model. .H\ZRUGV dual-process models, probability judgment, reasoning. ,QWURGXFWLRQ In this paper we investigated probability judgments. Participants had to judge which of two samples provided the best chances of picking a target. Participants are known to have the tendency to base their responses on a comparison of the absolute frequencies of the target instead of on the ratios (Babai, Brecher, Stavy, & Tirosh, 2006; Falk, Falk, & Levin, 1980; Green, 1983). In other words, they neglect the denominators in their judgment. Sometimes the judgment based on the absolute frequencies of the targets (e.g., black marbles in a box containing both black and white marbles) will be FRQJUXHQW with the judgment based on the ratios (e.g., Figure 1a), but the task can easily be modified to create an LQFRQJUXHQW item (e.g., Figure 1b). Comparison of the absolute frequencies of the targets then no longer results in correct probability judgments. The basic congruency effect (i.e., the lower accuracy for incongruent trials than for congruent ones) has been demonstrated before, but the extension of this experiment comparing dual-process accounts is novel. We will first introduce the general dual- process framework. According to the dual-process view, people have two systems for decision-making: one fast, automatic, and heuristic based, and the other slower, constrained by working memory (WM) capacity, and analytic (e.g., Evans 2008). Even though heuristic processing often leads to correct judgments, it can also bias reasoning in some situations (the incongruent conditions). Dual-process researchers posit that participants have a tendency to rely on heuristic processes instead of on analytic processes. This way, they can account for participants’ failure to provide the normatively correct responses on a range of reasoning tasks. The dual-process framework is frequently used to interpret performance when judging probabilities. That, is the tendency to rely on a comparison of the absolute frequencies of the targets would result from heuristic or intuitive processes (e.g. Babai, et al., 2006; Reyna & Brainerd, 2008; Stavy & Tirosh, 2000). A judgment based on a comparison of the ratios on the other hand would be the outcome of analytic processes. Evidence for a dual-process account of performance on this task was found in that correct judgments on congruent items and incorrect judgments on incongruent items have been observed to correspond with smaller latencies than correct responses to incongruent items (Babai et al., 2006). Also, under time pressure the congruency effect increased (Gillard, Van Dooren, Schaeken, & Verschaffel, 2008). That is, more errors were made on incongruent items, whereas accuracy remained unchanged for congruent ones. In the
Institution: KU Leuven
Language: English
Subfield: General Decision Sciences
Field: Decision Sciences
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W180688173