While teaching categorical data analysis in an educational psychology department, we
found that the textbooks currently available for categorical data analysis courses, although
very good, are frequently too technical and require a more extensive understanding of
mathematics than is typically the case for many students and researchers in the social
sciences. Therefore, our approach in writing this book was to focus on the concepts and
applications, rather than the technical details, of common categorical data analysis methods. We do present theory along with some technical details, as we believe these to be
extremely important components of understanding statistical methods, but the main focus
in this book is on conceptual understanding and application. In this way, not having extensive training should not prevent students and researchers from being able to understand
and apply these statistical procedures.
The main goal of writing this book was to provide an accessible resource on categorical data analysis to students and researchers in the social and behavioral sciences. This
book is intended to serve students and researchers in fields such as education, psychology,
sociology, and business as well as many others that require the analysis of categorical
variables. The book is primarily intended for a course in categorical data analysis or crossclassified data analysis, which is typically taught at the graduate level in the behavioral
and social sciences, and will probably require one or two prerequisite statistics classes
that cover conventional statistical methods (e.g., factorial analysis of variance, multiple
regression). Some experience with statistical software is also expected, although we provide extensive examples and instructions for using both SAS (version 9.1.3) and IBM SPSS
18, which we refer to as SPSS in this book (SPSS was acquired by IBM in October 2009