Diagnostic reasoning with causal models
Final Report Abstract
When humans engage in reasoning to find the cause of events or facts they observe, they are strongly influenced by their initial hypotheses and they use their knowledge about the ways in which potential causes can bring about events and facts. We used quasi-medical tasks in our research but the results presumably generalize to many kinds of diagnostic reasoning, for example, reasoning about causes for the behavior of other people or reasoning about the cause of malfunctions of technical equipment. In diagnostic reasoning, humans try to make sense of their observations and they are often successful. Difficulties arise if observations are ambiguous and it is necessary to decide between several plausible causes. Our results show that then the initial ideas about a possible cause can have an unjustified advantage that, for example, can lead to false medical diagnoses. We have investigated diagnostic reasoning with a novel method that records eye movements and reveals participants’ developing ideas about causes and their changing interpretations of symptoms while the participants think about symptoms they hear. The method makes use of the tendency to look at the former location of information that is needed in reasoning, for example, the tendency to look at a closed book while talking about its content. This novel tool developed in the project has been successfully applied to study decision making as well. It will be useful in research on a wide variety of reasoning tasks. In reasoning about potential causes to explain observations, humans presumably apply a specific kind of knowledge that enables them to reason about how causes produce effects. Recently, this kind of knowledge has been described as similar to schematic models of causal processes including chains of root causes, intermediate causes, and effects. Several experiments in this project have tested whether diagnostic judgments indeed turn out as if participants had used a mental causal model. Our results support theories postulating mental causal models in diagnostic reasoning but are still open to alternative explanations. We did not expect that the bias to interpret symptoms in favor of the initial diagnostic hypothesis would be so strong that it even showed up in tasks and procedures that previously had been thought to prevent such a bias. In our tasks, the symptoms were often more ambiguous than in previous studies and, apparently, ambiguous symptoms are particularly prone to biased interpretation. Welcome surprises were the power and the robustness of the process tracing method developed in this project. Memory indexing is very efficient compared to other methods and eye movement patterns could be replicated with remarkable stability after one week.
Publications
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(2012). Memory indexing of sequential symptom processing in diagnostic reasoning. In N. Miyake, D. Peebles, & R. P. Cooper (Eds.), Proceedings of the Thirty-Fourth Annual Conference of the Cognitive Science Society (pp. 497-502). Austin, TX: Cognitive Science Society
Jahn, G., & Braatz, J.
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(2012). Memory Indexing: A novel method for tracing memory processes in complex cognitive tasks. Journal of Experimental Psychology: Learning, Memory, and Cognition, 38, 1622-1639
Renkewitz, F., & Jahn, G.
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(2012). Order effects in diagnostic reasoning with four candidate hypotheses. In N. Miyake, D. Peebles, & R. P. Cooper (Eds.), Proceedings of the Thirty-Fourth Annual Conference of the Cognitive Science Society (pp. 905-910). Austin, TX: Cognitive Science Society
Rebitschek, F. G., Scholz, A., Bocklisch, F., Krems, J. F., & Jahn, G.
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(2014). Memory indexing of sequential symptom processing in diagnostic reasoning. Cognitive Psychology, 68, 59-97
Jahn, G., & Braatz, J.
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Parallel belief updating in sequential diagnostic reasoning. Proceedings of the Annual Meeting of the Cognitive Science Society, 36(36), 2014. PDF: 7 S.
Jahn, G., Stahnke, R., & Rebitschek, F.
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(2015). Biased processing of ambiguous symptoms favors the initially hypothesis in sequential diagnostic reasoning. Experimental Psychology, 62(5), 287-305
Rebitschek, F. G., Bocklisch, F., Scholz, A., Krems, J. F., & Jahn, G.
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The diversity effect in diagnostic reasoning. Memory & Cognition. July 2016, Volume 44, Issue 5, pp 789–805
Rebitschek, F. G., Krems, J. F., & Jahn, G.
