Original citation. White, P.A. (2008). Accounting for Occurrences: A New View of the Use of Contingency Information in Causal Judgment. Journal of Experimental Psychology: Learning, Memory, and Cognition, 34(1). 204–218.
Target of replication. White suggests that two kinds of information influence causal judgments: (i) the occurrence judgment, the extent to which the cause is present when the outcome occurs, and (ii) the strength of the cause as a generator of the outcome. We will replicate Experiment 3 of White (2008), which aimed at testing three predictions: (1) prediction 1 tested the cause prevalence effect (see also White 2004), i.e., that A+ (Cause A is present and the outcome occurs) instances should tend to raise judgment of A and lower judgment of B as Causes for the outcome; (2) prediction 2 aimed at demonstrating that Cause A should receive higher causal judgments than Cause B even if B may have a higher conditional contingency than Cause A (given the higher amount of occurrences of the effect when Cause A is present than when Cause B is present); (3) prediction 3 aims at testing whether manipulating the number of occurrences of the outcome given one cause when there are no nonoccurrences of the outcome (which does not change conditional contingency) affects causal judgments of the extent to which the cause can account for occurrences.
A priori replication criteria. We aim at testing the two main effects of prediction 1 and prediction 3. Given the 2 x 3 within factors design for both main effects, we calculated ηp² based on F-Values and degrees of freedom. This procedure resulted in ηp² = .427 and ηp² = .389 for the effect of prediction 1 (F(1, 36) = 22.88) and prediction 3 (F(1, 36) = 26.88), respectively. Accordingly, G*Power (Version 3.1) indicates that a power of 80%, 90%, and 95% is achieved with sample sizes of 3, 4, and 4 participants, respectively, for both effects (assuming a correlation of r = .5 between repeated measures in all power calculations).
Conclusions. In sum, the replication of Experiment 3 by White (2008) confirmed prediction 1, and 3; evidence for prediction 2, however, was only found partly. In line with the original study, there was no task in which ratings of A were significantly higher than ratings of B, even though the conditional contingency for A was always +1 and that for B was always less than +1. Interestingly, despite the similarity in our results, ratings for Cause A and Cause B were much higher in the sample of German students than the sample of British students by White.