Presenting geographic information: Effects of data aggregation, dispersion, and users' spatial orientation

Geographic information systems (GIS) have taken on an increasingly importan t role supporting decision making in many organizations. GIS have been used to support a breadth of tasks including oil and mineral exploration, facil ity location, logistics support, and facilities management decisions. The e ffectiveness of GIS as a decision support tool comes primarily from the vis ual display of data in the form of maps. When presenting information as a g eographic map, the level of data aggregation potentially affects aspects of task complexity such as information load and the potential for pattern rec ognition by the user. Other task attributes expected to be related to data aggregation effects include problem size, the degree of data dispersion, an d users' spatial orientation skills. We conducted an experiment to study these effects and their interactions. S ubjects used a GIS including map-based information characterized by differe nt levels of problem size, data dispersion, and data aggregation. Spatial o rientation skill was examined as a covariate in the experimental treatments . The results indicate that all of these geographic information characteris tics have significant impacts on decision performance. Moreover, many inter actions are present among the factors. We evaluate these interactions in or der to derive implications for practice and for future research.