GeoVSM: An Integrated Retrieval Model for Geographic Information

Geographical information exists in multiple forms such as cartographical maps, images, and texts. Effective retrieval systems for geographical information are currently studied by both geospatial information scientists and library/information scientists. The two groups take quite different approaches which have rarely been explicitly compared and connected. This paper discusses the advantages and limitations of current geographical information retrieval (GIR) and textual information retrieval (IR) systems in dealing with multimedia geographical information, and proposes a new retrieval model, called GeoVSM (Geographical + Vector Space Model), which integrates coordinate-based geographical indexing with keyword-based vector space model in representing information space. Document ranking by relevance is supported by document-query similarity measure taking into account degree of relevance in both spatial domain and thematic domain. To support visual query and browsing, GeoVSM model recognizes the fundamental differences in the dimensionality and configuration of geographical space and thematic space, and demands multi-view visual interfaces based on a “world” metaphor and a “desktop” metaphor. As an example of such interfaces, GeoVIBE is presented that supports a coordinated GeoView and a VibeView for smooth integration of two browsing strategies using geographic clues as well as thematic clues provided by users.