The center where I work provides demographic services to school districts, among other clients. We provide enrollment forecasts, school siting advice, and help adjusting boundaries. Data utilized in these studies include census information, student data, vital statistics, and data and reports from local planning agencies. Maps play an important role as a source of data.
Maps also are important in conveying information back to the district's citizens and administrators.
The issue addressed here is mapping of point data such as address matched student data. Simple pin maps showing where students live are helpful in conveying basic ideas about geographic distributions. However if one attempts more complex point maps, the use of heterogeneous point symbols often is not visually effective. Data that are spatially smoothed and averaged using grid maps do allow us to convey a sense of more subtle geographic distributions. This paper shows how the theme of net-migration of student households can be conveyed using grid mapping techniques.