Until recently, the Los Angeles police online crime map showed the 200 block of West 1st Street as most likely place to be victimized by crime, says the Los Angeles Times. The spot a block from the new police headquarters actually is quite lawful. The crimes reported there happened somewhere else. The only thing they had in common was an address that proved impossible for a computer to find. The distortion, which the police department wasn’t aware of until alerted by the Times, illustrates pitfalls in the growing number of products that depend on “geocoding” to convert written addresses into points on electronic maps.
In competition for Internet viewers, newspaper websites and online-only publications such as EveryBlock.com use commercial geocoding to map large bodies of data including crime reports, traffic accidents, pothole locations, liquor licenses and the homes of registered sex offenders. “Most spatial data are inaccurate,” said Paul Zandbergen, a professor of geography at the University of New Mexico who studies the quality of online maps. “It’s much easier to go the path of ‘let’s build it and not worry about the quality.’ And that’s been the trend since we started doing mapping.”