01 – Introduction & Linear Regression Refresher

Categorical Data Analysis (Soc 681) · Purdue University · Fall 2026

The lecture notes for this section of the course, with the Stata and R code and output for every example. This site contains all the material and code for the course. If you prefer the slides in PDF format and/or the Stata replication do-file, these can be downloaded at: lecture slides · replication code.

Acknowledgments

The outline of this class and these lecture notes have been heavily influenced from classes I have previously taught with Scott Long and Shawna Smith. My thanks and acknowledgments to them for providing their notes and advice for me to build on. I’ll take credit for any mistakes. - TDM

Contents

• 1.0 Categorical Data is Everywhere
• 1.2 Linear Regression (sans math)
• 1.3 Linear Regression (with math)
• Appendix A1: Datasets for Assignments
• Appendix A2: Stata Appendix