Data Analysis

    10 - 12 Grades Social Science
This module is part of a series produced at The Universtiy of Nevada at Reno for the National Numeracy Network under a grant from the Woodrow Wilson Fellowship Foundation through the National Council on Education and the Disciplines. These brief modules are envisioned as a resource for teachers to use in a classroom setting and also for quantitative literacy workshops for teachers. Each module typically contains one or two examples related to "real world" quantitative literacy issues and includes exercises for students. There is also a section "for the instructor" that contains discussions of some of the topics, solutions to the exercises, and resources for further explorations.


Misleading Aggregates:
Simpson's Paradox
Jerry Johnson
Universtity of Nevada

The verb to aggregate means "to collect or gather into a mass or whole." If you lump data together (aggregate it) you may get one picture, whereas if you break the data down into categories, you may get a very different picture - sometimes a seemingly contradictory one. The phenomenon is called "Simpson's Paradox." The examples in this module illustrate how this can happen and why one should be cautious before drawing conclusions from numbers. The mathematics involved is arithmetic and percentages.

The mathematics involved is arithmetic and percentages. Suggested grade levels: 12 and up due to subject matter and reading levels.