Batch Address Verification and Geocoding

USC has developed a new site for geocoding address data which is free - https://webgis.usc.edu - It can process databases of addresses or single ones and does address parsing and normalization on the addresses first automatically. This might be what you are looking for.

From first hand experience - after you do the geocoding - whether it be a single or batch geocoding - I have found it necessary in most cases to try to verify the coordinates with Google Earth or one of it's "equivalents" in an attempt to insure coordinate accuracy.

It nailed my home address, it looks like it is the coordinates of where I am sitting in my house.... Spooky

I am anxious to try it with some of the pois I maintain...

I just tried 3 geocoding sites with my address:

https://webgis.usc.edu returned a solution 1 mile away from my house.

GeoCoder was within 1 house

GPSVisualizer was within 2 houses

I double checked my coordinates with my Magellan eXplorist 100

It wasn't even close... But it was an address in a newly developed area, gpsvisulizer did do a better job, the person who submitted the correction matched the location given by the store finder... It's been said many times the geodecoders may get you close but you still have to confirm the information...

Edit: When I used my home address I used my complete zip code (xxxxx-xxxx), this may have made it much more accurate. I guess you could look up complete zips at the usps.com... I'll have to check that out.

Edit edit: I just tried the same address with the complete zip:407 GEORGE CLAUS BLVD SEVERN MD 21144-1317. It is the address of a Walmart. USC site was unable to decode it. Gpsvisulizer gave the coordinates of: 39.103380, -76.685739. Actual coordinates are: 39.145138 -76.648425.... So at least the USC site didn't give me incorrect coordinates..
BTW You can get complete zips at usps.com...

It put my house 3 houses east of where it's supposed to be, which is what all of the geocoding sites do. It also said my block went up to 1998 so I had it geocode that address and it put it in the middle of the next street west of me. My block goes to 1972.

None of the replies so far have addressed the OP's main point - that of Geocoding interfaces that returned degraded results (wild guesses?), without telling you.

(If you dig around in this forum long enough, you'll find a post by GPSVISUALIZER's owner, explaining that the result precision is not available through the AJAX interface to the Yahoo! Geocoder, used for Batch Geocoding.)

I do have a solution, but it doesn't meet the OP's requirement of being free.

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GeePeeEx Editor's Batch Geocoder interface has a pull-down option: 'Minimum Precision Required' So if you've specified "Address" level precision and Yahoo!'s Geocoder returns the coordinates of the city-centre instead, that result will not be used.

No coordinates or a message or ???

If you recall, it changes the colour of the entries it's geocoded - so you can see at a glance, the ones that require attention.
Or, you can set an option to abort the run on a failure. It depends if you want to fix one at a time, or sort out all the 'duds' together.

I just ran the Combined WalMart file through GeePeeEx batch decoder and about 300 or so of them failed.... That means just a street or city was used, hopefully they are all closer than a state... I can see what I'll be doing for a while...

The USC geocoder https://webgis.usc.edu may fail in some cases, but it does tell you what accuracy the (degraded) output geocode is - to the level of geographic feature matched. See toward the bottom of https://webgis.usc.edu/Services/Geocode/TechnicalDetails.asp... - If you process a database, you can sort by this quality field to see the ones that are of less-than-desirable accuracy without having to pick through the records one by one.

I use a few but all are not to reliable.. I will love to try this one too.. will let you know what i think.