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The Case of the Two-Faced Data


Rachel L. Rossetti
Department of Mathematics
Agnes Scott College


This case study on Simpson's paradox is a fictionalized account of a famous case of alleged gender discrimination at University of California at Berkeley. "Jane Eyre" was a young woman who applied to the top Ph.D. programs in English in the United States. A seemingly perfect candidate, Jane was accepted to all but one program, "Bronte University." What went wrong? In aggregate, Bronte University's graduate school admitted a higher percentage of male applicants than female applicants, suggesting possible gender discrimination. But when the numbers are broken down into individual departments, we learn that each department actually admitted a higher percentage of female applicants than male applicants. This is the basis of Simpson's paradox: a trend appears in two separate groups that disappears when the two groups are combined. Students completing the case engage in a combination of individual work, small group discussion, and summative whole-class discussions. Originally developed for a college-level math for liberal arts course, the case is adaptable to any course in which students work with data that may lead to Simpson's paradox.

  • Describe the presentation of Simpson's paradox.
  • Describe the cause of Simpson's paradox.
  • Explain how data can be manipulated to support two opposing statements.
  • Critique the presentation of data in media sources (if the optional current events assignment is used; see Variations and Assignments below).
Keywords: Simpson’s paradox; data; statistics; mathematics; gender bias; discrimination; aggregate data; trend
Topical Area: Science and the media, Social issues, Social justice issues, Women in science
Educational Level: High school, Undergraduate lower division
Formats: PDF
Type/Method: N/A, Analysis (Issues), Debate, Directed, Discussion, Role-Play
Language: English
Subject Headings: Statistics   Mathematics  
Date Posted: 8/29/2019
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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