Non-linear analysis of categorical variables, that is, a variable that can sort objects into a limited number of distinct groups called `categories', is a useful technique for social scientists, particularly those who do survey research. This book introduces the reader to the application of a particular approach to categorical analysis, the GIFI system, or multiple correspondence analysis. Using illustrative examples from a variety of disciplines, van de Geer shows how to perform these techniques using standard computer programs, such as SPSS. The book explains when to use particular programs, what conditions need to be met for effective use of each program, and how to interpret the results based on the use of each of these programs. Detailed examples are used throughout the book to enable the reader to comprehend what is `going on behind' the computer program.