Google Maps vs. Virtual Earth: A geocoding accuracy showdown in West Palm Beach
Careful readers will have noticed I have a certain admiration for Microsoft’s Live Search Maps and the broader Virtual Earth platform. Not only is it a worthy competitor to Google Maps, but in some respects it’s a superior product. Mileage may vary depending on your location and needs, but I have crazy love for Virtual Earth/Live Maps down here in South Florida. Even casual readers will know that I find Virtual Earth’s oblique aerial imagery mind-blowingly awesome, whereas I think Google’s Street View is merely awesome. Like in a “check out my awesome four-slice toaster” sort of way. Too, most of Microsoft’s imagery in South Florida appears to have been shot in early 2007, while Google’s looks 2005-ish at best.
Image quality and recentness aside, colleague and all-around brainy fella Matt Wensing last week ran across another issue that I haven’t seen mentioned before: Geocoding accuracy. As in, Google isn’t very good at it, at least compared to Virtual Earth, and at least in Palm Beach County. Matt passed 400 random West Palm Beach addresses to both Google Maps and Virtual Earth. We happen to know the actual center point of these parcels, so he compared the distance from that exact point to the coordinates returned by each mapping service’s big, black and seemingly unknowable geocoding box. Hit the jump to read about the results and download the test points. Or be totally lame and don’t hit the jump. See if I care.
In the head-to-head, closest to the pin contest, Microsoft’s geocoder beat Google’s in 341 of 400 cases, with four ties. That’s an 85.25 percent winning percentage for Virtual Earth, people. Not too shabby for a mapping service about which almost no one outside mapping circles appears to have heard. Google’s average error was 509 feet, with a median of 149 feet. Microsoft’s geocoder was off by an average of 366 feet, with a median of 83 feet.
Here’s one not even particularly dramatic example. The true property is highlighted in red, with Google’s pin six houses down the street.
And here’s how Microsoft did. That’s the actual house obscured by the pin.
So, what say you, super mapping geek who actually read to the end of this post? Are we missing something here? Or should more developers look at Google Maps not as the default in this space, but merely one of several serious options?
Mash your mouse here to download the test points and results (Excel worksheet, 121 KB)