This report makes available in condensed form the methods for performing longitudinal studies of attitude change and the issues associated with these methods. It represents a state-of-the-art review of such methods, and the material covered spans the disciplines of psychology, sociology, and statistics. It is meant to provide a brief description of the tools available, references to more detailed descriptions, and an overview of the theoretical and practical issues involved in execution and interpretation to those wishing to employ longitudinal methodology. The report is divided into the following four sections: (a) Longitudinal design and cross-sectional design are compared in terms of relative advantages and disadvantages. (b) Theoretical issues associated with studies done over time, such as the overcorrection/the overall variance, are discussed. (c) Actual methods are described; this section is subdivided into (a) experimental designs, (b) quasi-experimental designs, and (c) statistical techniques. This section also includes references to actual studies in which these methods were employed. (d) Practical considerations in doing longitudinal research are discussed. The major conclusion drawn in the report is that while sophisticated methods are available for use, overall development of the field is being hampered because work progresses independently in several disciplines. (Author)