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Web Visualization: Chi-square contingency analysis

This web visualization simulates samples of a 2x2 contingency analysis. It demonstrates that the χ2 test statistic follows a χ2 distribution and illustrates the meaning of the P-value. It may be most useful as a demonstration of the meaning of Type I error and power. This visualization has no tutorial version.
Prerequisite Knowledge
Students using this visualization should
- recognize when a contingency table is an appropriate way to summarize a data set;
- identify and distinguish between a population and a sample, and between parameters and statistics;
- explain the concepts of sampling variability and sampling distribution.
Learning Objectives
- Investigate the chi-squared test for independence between categorical variables, including the sampling distribution of the test statistic.
- Interpret the meaning of the P-value associated with a contingency analysis.
- Explain the two types of error possible and the power of a hypothesis test.
- Investigate the effects of the sample size and population parameters on the power of the chi-squared test.
Suggested use(s) and tips
These resources are intended to be used in a number of ways
- as a visual aid during lectures;
- as an open-ended learning tool for active learning;
- as a guided learning experience, using either the built-in tutorials or the guided activity sheet or other instructor-supplied material.
About this Resource
Funding: University of British Columbia
Project Leader: Mike Whitlock
Programmers: Boris Dalstein, Mike Whitlock & Zahraa Almasslawi
Art: Derek Tan
Translation: Rémi Matthey-Doret
Testing: Melissa Lee, Gaitri Yapa & Bruce Dunham
Thanks to: Darren Irwin, Dolph Schluter, Nancy Heckman, Kaylee Byers, Brandon Doty, Kim Gilbert, Sally Otto, Wilson Whitlock, Jeff Whitlock, Jeremy Draghi, Karon MacLean, Fred Cutler, Diana Whistler, Andrew Owen, Mike Marin, Leslie Burkholder, Eugenia Yu, Doug Bonn, Michael Scott, the UBC Physics Learning Group & the UBC Flex Stats initiative for numerous suggestions and improvements.
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