A Classroom Intervention to Reduce Confrmation Bias Elizabeth N. Hane 1 and Evelyn Brister 2 1 Gosnell School of Life Sciences, Rochester Institute of Technology 2 Department of Philosophy, Rochester Institute of Technology Abstract STEM students are often unable to recognize cognitive bias in their own disciplines, and simply describing cognitive bias to students has shown to be insuffcient to improve critical thinking. However, habitual metacognitive techniques show promise for correcting cognitive biases, such as confrmation bias, a maladaptive cognitive strategy that specifcally threatens the objectivity of scientists. As part of a course on metacognition in science, frst-year STEM students were asked to give an oral presentation about a controversial socioscientifc topic (e.g., GMO crops, de-extinction, or hydrofracking). The frst year the course was offered, presentations exhibited confrmation bias at a high rate, despite instructions to examine multiple viewpoints about the scientifc issue. In subsequent years, an intervention in the form of an interactive lecture/discussion/ activity about confrmation bias and two specifcally-designed homework assignments asked the students to refect on evidence, search processes and potential biases. This intervention was jointly developed by faculty members in biology and philosophy to focus on habitual metacognitive techniques. Compared to no intervention, the resultant presentations had a higher percentage of reliable sources and a lower percentage of citations that only supported their conclusion. These results indicate that after the intervention exercise, students were discriminating among sources more carefully (Mann-Whitney p=0.009) and were using more sources from the other side of the argument, including presenting more reasons that refute their own ideas (Mann-Whitney p=0.003). We fnd that providing classroom instruction supported by deliberate practice to counteract confrmation bias improves students’ evaluation of scientifc evidence. Citation: Hane EN, Brister E. 2022. A classroom intervention to reduce confrmation bias. CourseSource. https://doi.org/10.24918/cs.2022.7 Editor: Katie Burnette, University of California Riverside Received: 6/16/2021; Accepted: 9/19/2021; Published: 3/3/2022 Copyright: © 2022 Hane and Brister. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. The authors affrm that they either own the copyright to or have received written permission to use the text, fgures, tables, artwork, abstract, summaries, and supporting materials. Confict of Interest and Funding Statement: None of the authors has a fnancial, personal, or professional confict of interest related to this work. Supporting Materials: Supporting Files S1. Confrmation Bias – Homework Assignment #1; S2. Confrmation Bias – Cognitive Bias Lecture Slides; S3. Confrmation Bias – Puzzle Activity Handout; S4. Confrmation Bias – Homework Assignment #2; S5. Confrmation Bias – Presentation Instructions; and S6. Confrmation Bias – Presentation Rubric *Correspondence to: Gosnell School of Life Sciences, 85 Lomb Memorial Dr., Rochester, NY 14623. Email: enhsbi@rit.edu CourseSource | www.coursesource.org 2022 | Volume 09 1 Lesson INTRODUCTION People like to be right. It is unpleasant to be wrong, and it is hard work to revise beliefs. In recent decades, psychologists have revealed a number of cognitive biases that lead us to make poor decisions about what to believe, at least in the complex information environment in which we now live. “Cognitive bias” refers to predictable, systematic deviations from objective reasoning that occur due to misapplications of otherwise effective strategies for evaluating evidence (1). Under the infuence of cognitive biases, people feel like they are actively investigating evidence and searching for true beliefs, even though they are systematically prone to maintaining false ones. For instance, people tend to avoid challenges to their beliefs (confrmation bias); they tend to believe what the people around them believe, even when those beliefs are poorly justifed (false consensus bias); they preserve consistent sets of beliefs by denying the validity of disconfrming evidence (backfre effect); and then, when confronted with evidence that they are cherry-picking what to believe, they deny the possibility that they are biased in this way (blind spot bias) (1-3). Social and cognitive psychologists have revealed a number of biases that lead to reasoning errors. At the same time, examining whether evidence supports or disconfrms hypotheses is central to the pursuit of scientifc inquiry (5-6). Searching for exactly this Learning Goals Students will: • recognize cognitive biases that infuence their ability to be objective in science. • understand and use refective techniques to reduce confrmation bias when searching for evidence in a socioscientifc problem. Learning Objectives Students will be able to: • describe types of cognitive bias that are commonly encountered in the process of scientifc discovery. • utilize techniques to reduce confrmation bias in their own scientifc experiences. • evaluate sources of information and their role in the process of science. • apply the process of science to a socioscientifc problem, connecting science to societal issues.