The Seattle School District (Washington) assigns each of its students to a particular attendance area, gives that area a code name and computer designation called a geocode, then uses data processing methods to analyze the makeup of the student population in each area and to provide data for a number of planning purposes. The geoprocessing permits not only analysis of data in tabular form, but also graphic presentation of attendance patterns through computer-produced school district maps. The district updates its information weekly to provide current data applicable to desegregation planning, facility utilization and school closure planning, student school assignment, student transportation planning, geographic distribution of special programs, and enrollment forecasting. This report discusses each of these applications of the geoprocessing system and provides samples of the computer output associated with each use. (PGD)