This manual is designed to assist administrators of English-as-a-second-language programs in assessing students' language growth. It begins by reviewing some of the concepts and terminology to be used. It then goes on to suggest and illustrate data-recording formats and methods of summarizing raw gains. This is followed by an example based on bowling scores to illustrate the regression effect. An overview of a method for separating raw gain into regression and true gain components follows. It concludes with a brief discussion of a method for comparing two different groups with differing backgrounds or curricula. The appendices give details of the data and of the steps in performing the regression analyses using SPSS (Statistical Package for the Social Sciences).