Assimilation and Contrast Effects in Sequential Judgments

Based on my experiences both as a student actively taking exams and as an assessor passively journalizing exams, I was interested in the influence of prior on subsequent evaluative judgments in a sequential judgment situation. In most (written or oral) exam situations, the performances of different students are judged in a sequence. The basic idea, I started out from, was that in this case performances of different students to be judged during an exam are compared with each other; more precisely, I expected the performance judgment of a target student to be influenced by the performance judgment of the prior student. Thus, the prior student was expected to function as a comparison standard for the target student to be judged in an exam situation. This might have an assimilative as well as a contrastive effect on the judgment of the target student. In a first line of studies it was tested whether and in what direction judgments of prior performances would influence subsequent ones. Participants were in the role of a teacher and had to grade the performance of two students during an exam based either on written or oral protocols. The performance of the first student was manipulated to be either good or bad; additionally, the focus of participants was manipulated to be either on similarities or on dissimilarities via an ostensibly unrelated priming task. The results show that prior judgments may have an assimilative as well as a contrastive influence on subsequent judgments, dependent on the comparison focus of the judge. As suggested by the Selective-Accessibility Model (SAM, Mussweiler, 2003a), a similarity focus made assimilation effects more likely whereas a dissimilarity focus made contrast effects more likely. Over all three studies, assimilative influences were stronger than contrastive influences. This is in line with the SAM that describes assimilation effects as the default influence of a standard in comparative judgments. In a second line of studies, assumptions derived from the SAM concerning the processes underlying comparison effects on judgments were directly tested. The model suggests that prior to a judgment the target to be judged is compared with a given standard. During this comparison, judges follow and test either a similarity or dissimilarity hypotheses – employing a certain (positive) test-strategy – and will, thus, selectively activate information on which the final judgment of the target will be based. Participants were again in the role of a teacher and had actively to test two (or three) students in a virtual exam, using a computer-based simulation. Participants had to ask questions and received answers from the virtual students they had to grade in the end. The same variables as in the first line of studies were manipulated. The results show that participants used a positive test-strategy to test their hypothesis regarding the target student. They asked more difficult questions when expecting a well performing student than when expecting a badly performing student. The influence of this test-strategy was more pronounced at the beginning compared to the end of an exam, suggesting that participants were able to integrate (disconfirming) feedback and to adjust their hypothesis accordingly. To conclude, the first part of my work shows that comparisons may influence evaluative performance judgments in a sequential judgment situation. The second part gives first direct evidence for the assumption (derived from the SAM) that these effects are caused by an underlying process of (positive) hypothesis testing.