In this tutorial, we take the assembled Congressional District polygons from previous tutorials and add a field so that we can perform a join; we then join a spreadsheet of quantitative data, then export the file to an image file. This tutorial uses ArcGIS 9.3. For larger display and better resolution, click through to the original Vimeo page.
Elaborating on the potential complexities of the “Join” function for other projects, the column title and the formatting of the column must be the same in both the spreadsheet file you are using and in the shapefile’s .dbf (the data file among the 3 to 6 that make up the shapefile) or it will not work. You can make these alterations in a spreadsheet program like Excel or in a package like SPSS. In some cases, one file or the other is corrupted and you need to download or create a new file.