  This paper performs a quantitative comparison of open-source data available
on the Internet for the fine-grain mapping of land use. Three points of
interest (POI) data sources--Google Places, Bing Maps, and the Yellow
Pages--and one volunteered geographic information data source--Open Street Map
(OSM)--are compared with each other at the parcel level for San Francisco with
respect to a proposed fine-grain land-use taxonomy. The sources are also
compared to coarse-grain authoritative data which we consider to be the ground
truth. Results show limited agreement among the data sources as well as limited
accuracy with respect to the authoritative data even at coarse class
granularity. We conclude that POI and OSM data do not appear to be sufficient
alone for fine-grain land-use mapping.
