Why do I get different results using the alphanumeric geocoder?

[TimShields]

Hi,

I am geocoding a list of addresses using two different geocoders. One is US Streets and the other is US Alphanumeric Ranges. After geocoding, the alpha geocoder does not place addresses that the numeric locator places. Why is that?

Thanks,

Tim

[KristofVydt]

Tim,

There can be be several reasons for this. Both locators can have different reference data, since they have a different locator style. Also each locator style interprets the search address in a different way, and try to match it with specific fields in the reference data depending on its configuration.

If you look at the table of address locator styles in the online help (e.g. for ArcGIS Desktop 9.3 : http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Commonly_used_address_locator_styles), you can see:
- "US Alphanumeric" expects search addresses formatted like "N2W1700 County Rd." (using address grid zones)
- "US Streets" expects search addresses formatted "320 Madison St."

So, if you're searching an address described as house number + street name, a US Street style locator is likely to find it. But the US Alphanumeric won't because the house number is different from a grid zone.

I hope this clarified it a bit.

Kristof Vydt
Esri BeLux