[sgnelson]

Thanks for replying, your data sources are amazing, it must have taken quite a bit of work to put them all together.

And I get that different users have different needs, but I'm still curious about the accuracy (it's geography after all, I don't care how fast the results are returned if they're wrong.) And especially given the multi-data sets that OpenCage uses, how do you know that you're returning the right results? (obviously there is the spatial aspect, ie, within 100 yards of the true location; but I'm most curious about the percentage of returned address with a greater than 90% probability of being the "correct" address.) I wouldn't expect it from most geocoder services, but that's what "ground truthing" is for.And what happens if you happen to come across conflicting results when you're using the multiple data sets?

So again, all these new geocoders provide some nice services, but how are they measuring their accuracy of results? I could also shrink this question down to a business question, what makes your service better versus all the others? Who can prove to me that they provide the "best" (most accurate) results? (I'm not in the market, sorry, it's a hypothetical.)

[freyfogle]

I still think you're putting to much weight on accuracy as the key feature. We have plenty of customers who only care about having the correct town or postal zone or neighbourhood, and some even who actually do NOT want accuracy (due to privacy implications).

Nevertheless, yes of course I get what you are asking. Fundamentally all geocoders rely on someone having verified the input data, be it a government surveyor, a car taking pictures that are then evaluated (by humans and/or image processing software) or an OpenStreetMap volunteer, etc. We are at the end of a long data chain and have to trust the inputs we get.

In my 20% time I'm working on a world map at 1:1 scale which will solve this problem, hoping to launch next quarter ....