A needs assessment is a procedure or process that identifies the perceived or expressed needs of a school district. The process involves the use of various measurements and activities to obtain the data needed to define the gap between "what is" and "what should be." This handbook reviews four such processes or models for identifying needs. A planning overview explains what comprehensive planning consists of, the sequence of steps in the process, a generic planning model, and why a comprehensive planning process should be instituted in a school district. The overview is followed by a rationale for doing a needs assessment, the steps to begin, and the results that can be anticipated on completion of, a needs assessment. To aid in the selection of a model, the criteria used to choose the models for this handbook are presented, as well as a summary of each model and a matrix of model characteristics. A final section focuses on who is involved, what activities take place, and what happens after the needs assessment is completed in each model. Appendixes contain a list of definitions from each model, a list of questions to help districts evaluate a needs assessment, and one general and four selected short bibliographies. (Author/WM)