Geographic information retrieval
Geographic information retrieval (GIR) or geographical information retrieval is the augmentation of information retrieval with geographic metadata.
Information retrieval generally views documents as a collection of words, also known as a bag of words. In contrast, geographic information retrieval requires a small amount of semantic data to be present (namely a location or geographic feature associated with a document). Because of this it is common in GIR to separate the text indexing and analysis from the geographic indexing.
GIR systems can commonly be broken down into the following stages: GeoTagging, text and geographic indexing, data storage, geographic relevance ranking (with respect to a geographic query) and browsing results (commonly with a map interface).
GIR systems
GIR involves extracting and resolving the meaning of locations in unstructured text. This is known as Geoparsing.
After identifying location references in text, a GIR system must index this information for search and retrieval.
Evaluation
In 2005 the Cross-Language Evaluation Forum added a geographic track: GeoCLEF. GeoCLEF was the first TREC style evaluation forum for GIR systems and provided participants a chance to compare systems.