Urteilsverzerrungen beim Diagnostizieren von Fehlkonzepten bei Dezimalbrüchen

Learners’ misconceptions often manifest as recurring patterns when solving comparable tasks. Yet, a systematic error cannot always be directly and unambiguously attributed to a misconception. However, such accurate diagnosis is necessary if a teacher wants to implement adaptive instruction. To achieve accurate diagnosis, diagnostically relevant information must be processed. During information processing, cognitive biases may arise. Specifically, individuals may overlook the ambiguity of the situation and proceed to select further tasks and interpret their diagnostic relevance based solely on one misconception. The present study examines the presence of these judgment biases in the diagnostic judgments of prospective teachers (N = 79) by analysing how they process the information. In addition, the influence of the person’s preference for deliberation on information processing and possible judgment biases is examined.

The participants worked on five case vignettes in each of which they were confronted with an incorrect student solution in decimal fraction comparisons and were asked to make an unambiguous diagnosis of the misconception at hand. For this purpose, they generated initial diagnostic hypotheses and selected further tasks which the learner to be diagnosed would solve. The diagnostic relevance of the available tasks differed systematically. Based on the described model of judgment processes, it was possible to categorize information processing and cognitive bias (confirmation bias) with the collected data.

In our study, high judgment accuracy could be predicted through the processing of relevant information during the diagnostic process, but not through the perception of the ambiguity in the judgment situation at the beginning of the process. A preference for deliberate decision, i.e., a tendency to consciously integrate information, as a person characteristic had a positive effect on the number of formulated multiple hypotheses but had no effect on the selection of tasks and the accuracy of the final diagnosis.

The results provide initial evidence on the impact of judgment bias in teacher judgments and provide impetus for further research on diagnostic thinking. Therefore, we conclude with a discussion of possible interventions to reduce judgment bias in prospective teachers.