topic Re: Question about geocoding with “ArcGIS Online World Geocoding Service” in Address Points Questions

Question about geocoding with “ArcGIS Online World Geocoding Service”

FeodorGostjev — Tue, 21 Feb 2017 16:47:29 GMT

I have been teaching myself Geocoding in ArcGIS. I have a questions about how geocoding with “ArcGIS Online World Geocoding Service” works. I noticed that every time I use the online geocoding service, I get all of the addresses matched. This is the case even when geocoding the same addresses with a custom-made address locator produces several unmatched addresses. To look into this further, I created an address table with a few addresses purposely miss-spelled and a few missing street addresses altogether (with city name or zip code only). Once again, the custom-made address locator identified the errors I introduced but the online geocoding service still shows them to be a match but in this case to the city or zip code. I also noticed that the online service does not allow you to adjust geocoding options like spelling sensitivity. The bottom line is, I am concerned that I will not be able to identify addresses that were not matched to their street location when using the online service like if I was working with a custom-made address locator. Does anyone know why the online service does not identify unmatched addresses?

Re: Question about geocoding with “ArcGIS Online World Geocoding Service”

JoeBorgione — Tue, 21 Feb 2017 17:04:25 GMT

I don't use Online Geocoding services, but when you mention "the online geocoding service still shows them to be a match but in this case to the city or zip code" it makes me think that the online service is using a composite locator, and when it doesn't get a hit on the actual street address, it moves on 'in the stack' of locators and gives you a match on the city or zip, which may be two additional locators in the composite.

Subsequently, those 'matches' would be to the centroid of the respective zip or city polygon. Depending on your use of the resulting data, that level of accuracy may or may not be acceptable.

Re: Question about geocoding with “ArcGIS Online World Geocoding Service”

FeodorGostjev — Tue, 21 Feb 2017 17:18:31 GMT

That is actually exactly what I was thinking, especially regarding the online service using a composite locator. There is actually a field that tells you whether each address was matched to "StreetAddress" "Postal" etc. Basically, what I am getting out of this is that I should use a custom-built address locator if one (or reference data) is available and only use the Online service when there are no other (inexpensive) options.

Re: Question about geocoding with “ArcGIS Online World Geocoding Service”

JoeBorgione — Tue, 21 Feb 2017 18:03:04 GMT

I manage and maintain all the data I geocode to which includes centerlines and address points for my area of operation. It's used in 9-1-1 dispatch so missed addresses have big consequences...

Re: Question about geocoding with “ArcGIS Online World Geocoding Service”

BruceHarold — Wed, 10 May 2017 13:55:57 GMT

Feodor, Joe

The World service indeed uses composite locators. If you use the Geocode Addresses geoprocessing tool then no control over match type is exercised and what you see in the Addr_type output field tells you what type of match was made. If you need to confine matching to point and street centreline matches you can do this programmatically with the REST API by supplying a category filter. I can provide a Python script tool for the purpose, message me with your email.