Epistemic Practices of Coordinating Conflicting Data With Competing Theories

• In Event: Promoting Epistemic Practices in Science Classes

Abstract

Objectives and theoretical framework. In daily life, people encounter contradictory theories, claims, and evidence. Reaching sound decisions (e.g., “Which cancer treatment shall I choose?”) requires a high level of skill at the epistemic practice of reasoning well about contradictory information. Much research has examined such reasoning; however, many studies employ short tasks (e.g., Richter & Schmid, 2010) and/or vignettes with very little information (e.g., King & Kitchener, 1994). In contrast, we presented students in multiple interview sessions with a rich set of authentic evidence bearing on the cause of the disease pellagra, to understand how people grapple with contradictory information in more realistic situations (Chinn & Malhotra, 2002). As in the real history of research on the cause of pellagra, the evidence was conflicting, with some studies seeming to support a bacterial theory and others supporting dietary deficiencies as the cause. The actual cause is niacin deficiency.
The goal of our study was to gain insights into how students develop explanatory frameworks when faced with a mix of supporting, irrelevant, and contradictory evidence. We take the perspective that students actively construct theoretical frameworks for making decisions in the face of contradictory evidence and that those frameworks are intelligible and interrogable (Chinn & Brewer, 2001).
Data sources and methods. Interviewees were 33 seventh graders from a diverse urban middle school and 34 undergraduates from a public university. Students read a total of ten counterbalanced authentic epidemiological studies one by one and answered a short series of recurring questions, posed by a trained interviewer, aimed at encouraging them to use the evidence to construct a theory of the cause of the disease. At regular intervals students were prompted to reflect on the relationships between their current explanatory framework and the evidence they had previously encountered, including contradictory evidence. Our analyses focus on their responses to these prompts. Responses were coded using grounded theory approaches.
Selected results. (1) There were no significant differences between undergraduates and seventh graders. This suggests that secondary schooling and the first semesters of university promoted little or no growth in students’ reasoning practices. (2) Because the studies were contradictory, all participants should have been able to identify evidence conflicting with their current theory, but 1/3 of the students were unable to identify even one contradiction. (3) Students explanations for contradictors were generally of low quality, such as simply stating that the contradictory evidence was an anomaly, without attempting to resolve the contradiction, or by “subtyping” with implausible reasons for the discrepancies. (4) More sophisticated responses, such as suggesting that scientists in a contradictory study may have neglected key variables in their study design or analysis, were infrequently invoked by students of any age, although nearly all the studies afforded these responses.
Significance. It is therefore clear that students, at both the seventh grade and undergraduate level, need more opportunity to work on authentic ill-structured scientific problems involving contradictory evidence in an inquiry environment. Our study identifies particular strategies for resolving contradiction that could be the focus of instruction.

Authors

• Clark A. Chinn, Rutgers University

• Ron Rinehart, Rutgers University