Survey Documentation and Analysis (SDA) allows you to subset variables or cases for analyzing or downloading and produce crosstabulations, descriptive statistics, and frequencies for selected studies. Eventually, many or all of the studies in NACDA's holdings will be available for use with the SDA. SDA was developed at the University of California. The following SDA data files are available from the NACDA collection. We encourage you to explore these data using the SDA system. The best way to see how the system works is to try it out. We welcome your suggestions and comments.