| How does GIS overlay integrate geographic information? I approach this question by considering the joint technological and social construction of GIS technology. The research presented here considers four aspects: (1) the history of geographic integration and the shift in geographic thought from holism to systems; (2) the cultural mediation of technology; (3) the abstraction and representation of geographic information; (4) the development of layers and overlay as analytical methods in geography.;Two case studies of current county GIS implementations, one in the US and one in Germany, elaborate the social construction of GIS technology emphasizing the pertinence of cultural factors.;The historical development of the idea of geographic integration illustrates a shift from holistic concept of geography to systems approaches, e.g., Hartshorne's "sum of parts." The claim that the system's approach can be holistic guides the development of GIS technology. However, sociological analysis shows that the system always has a distinct purpose that limits a particular system. Systems are parts of the whole, fitting distinct social worlds, mediated by cultural values and meanings.;Negotiations lead to boundary objects that provide a common reference point to translate between different institutions and people. Coercion or consensus is not necessary. They retain the integrity of each social world, but establish commonalities. Technological artifacts are boundary objects, such as the wetlands layer. The social construction of geographic information technology for shared geographic space between multiple heterogeneous participants, is a process of negotiating boundary objects and standardized packages. Standardized packages consist of artifacts, theories, and methods that become the accepted technology.;GIS overlay is a technique that facilitates the combination of different understandings of geographic phenomena. This technique follows a complex set of culturally and disciplinary mediated methods for conceptualizing geographic phenomena and cartographically representing them. Geographic integration is the social construction of boundary objects in these disciplinary settings that fulfill multiple constraints and purposes.;Cultural factors mediate the construction of GIS technology and geographic integration. Geographic information integration, whether through GIS overlay or through other means, is contingent on the geographic affinity of boundary objects. It is the social production of geographic knowledge. |
