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Pick Your Poisson: A Tutorial on Analyzing Counts of Student Victimization Data

NCJ Number
Journal of School Violence Volume: 11 Issue: 3 Dated: July - September 2012 Pages: 187-206
Francis L. Huang; Dewey G. Cornell
Date Published
July 2012
20 pages
This research examined how Poisson-based regression techniques can be applied to school violence research.
School violence research is often concerned with infrequently occurring events such as counts of the number of bullying incidents or fights a student may experience. Analyzing count data using ordinary least squares regression may produce improbable predicted values, and as a result of regression assumption violations, result in higher Type I errors. Count data are optimally analyzed using Poisson-based regression techniques such as Poisson or negative binomial regression. We apply these techniques to an example study of bullying in a statewide sample of 290 high schools and explain how Poisson-based analyses, although less familiar to many researchers, can produce findings that are more accurate and reliable, and are easier to interpret in real-world contexts. Abstract published by arrangement with Taylor and Francis.