Median Splits, Type II Errors, and False Positive Consumer Psychology: Don't Fight the Power

51 Pages Posted: 20 Mar 2015 Last revised: 10 Apr 2015

See all articles by Gary McClelland

Gary McClelland

University of Colorado at Boulder - Department of Psychology

John G. Lynch

University of Colorado-Boulder, Leeds School of Business - Center for Research on Consumer Financial Decision Making

Julie R. Irwin

University of Texas - McCombs School of Business

Stephen A. Spiller

University of California, Los Angeles (UCLA) - Anderson School of Management

Gavan J. Fitzsimons

Duke University - Fuqua School of Business

Date Written: April 9, 2015

Abstract

Considerable prior statistical work has criticized replacing a continuously measured variable in a general linear model with a dichotomy based on a median split of that variable. Iacobucci, Posovac, Kardes, Schneider, and Popovich (this issue) defend the practice of “median splits” using both conceptual arguments and simulations. We show that both their conceptual arguments and their simulations range from incomplete to incorrect. There are no real benefits to median splits, and there are real costs in increases in Type II errors through loss of power and increases in Type I errors through false positive consumer psychology. Median splits remain a bad idea.

Keywords: ANOVA, regression, median split, dichotomize, power, Type II errors

Suggested Citation

McClelland, Gary and Lynch, John G. and Irwin, Julie R. and Spiller, Stephen A. and Fitzsimons, Gavan J., Median Splits, Type II Errors, and False Positive Consumer Psychology: Don't Fight the Power (April 9, 2015). Available at SSRN: https://ssrn.com/abstract=2580320 or http://dx.doi.org/10.2139/ssrn.2580320

Gary McClelland (Contact Author)

University of Colorado at Boulder - Department of Psychology ( email )

Boulder, 80309
United States

John G. Lynch

University of Colorado-Boulder, Leeds School of Business - Center for Research on Consumer Financial Decision Making ( email )

Leeds School of Business
Boulder, CO 80309-0419
United States
919-971-5201 (Phone)

HOME PAGE: http://https://www.colorado.edu/business/john-g-lynch-jr

Julie R. Irwin

University of Texas - McCombs School of Business ( email )

Business,Government and Society Department
Austin, TX 78712
United States

Stephen A. Spiller

University of California, Los Angeles (UCLA) - Anderson School of Management ( email )

110 Westwood Plaza
Los Angeles, CA 90095-1481
United States

Gavan J. Fitzsimons

Duke University - Fuqua School of Business ( email )

Box 90120
Durham, NC 27708-0120
United States

Here is the Coronavirus
related research on SSRN

Paper statistics

Downloads
260
Abstract Views
1,206
rank
121,884
PlumX Metrics