Andrew F. Hayes, Ph.D., is Professor of Quantitative Psychology at The Ohio State University in Columbus, Ohio, USA. He holds a Ph.D. in Psychology from Cornell University as well as a B.A. in Psychology from San Jose State University. His research and writing on data analysis has been published in such journals as Psychological Methods, Multivariate Behavioral Research, Behavior Research Methods, British Journal of Mathematical and Statistical Psychology, and Psychological Science, among others. He is the author of Regression Analysis and Linear Models (2017) and Introduction to Mediation, Moderation, and Conditional Process Analysis (2013), both published by The Guilford Press, as well as Statistical Methods for Communication Science (2005), published by Routledge. He also invented the PROCESS macro for SPSS and SAS, now widely used by researchers examining the mechanisms and contingencies of effects. He teaches data analysis primarily at the graduate level and frequently conducts workshops on statistical analysis throughout the world. He can be located in cyberspace at www.afhayes.com.