(e.g., Visual Basic in the case of ArcView and MapInfo). Using existing functionality as the building blocks, a programmer can develop special-purpose methods. Both ArcView and MapInfo connect to Visual Basic at the interface level, but the core of the GIS software is not directly accessible. Once new functionality is constructed, it can be made accessible by connecting it with menu items added to the interface. By contrast, a GIS such as Smallworld has a much smaller core, with most of the functionality and interface being developed using a custom-built programming language called Magic. Using Magic, developers can engage in “deep editing” in which the core functionality can be changed or augmented in major ways. The ability to customize software with the use of programming languages to meet the specific needs of students would be valuable in the K–12 context. Customization does, however, place significant demands on the curriculum developer or teacher.
From this analysis, four points can be made about the capacity of GIS to perform functions.
GIS is a very powerful tool for performing transformations, operations, and analyses.
The capacity of most GIS software to perform functions is greater than K–12 students require.
The complexity of existing product functionality is greater than is desirable for the K–12 context.
The flexibility to add functionality, although attractive and desirable, may be too challenging in most educational settings.