The Outer Match Score

The outer match score indicates how much Validate Global Address changed each address line to validate the address. The score compares the address lines before standardization and after validation and formatting. This score is only generated if you set the option Outer match score lines to a value greater than 0.

The outer match score is similar to the validation match score, which is part of the ACR code (see The ACR Code). The difference is that the outer match score measures any change to an address line, including formatting, whereas the validation match score measures only whether or not the data could be validated,

For example, take the following input address lines before processing:

Address Line 1: 5 camden cres
Address Line 2: bath
Address Line 3: uk

After processing the address lines are:

Address Line 1: 5 Camden Crescent
Address Line 2: Bath
Address Line 3: BA1 5HY
Address Line 4: United Kingdom

This has a validation match score of 84% and in outer match score of 23%.

The validation match score is high because the address components were fairly accurate before validation. The street name was valid except for casing and use of an abbreviation. The city and country were both valid. The only thing not correct was the postal code (in this case it was missing). Hence the relatively high validation match score of 84%.

The outer match score is low because after formatting, the address lines are considerably different from the input. In this case, Address Line 3 contained "uk" on input, and contains "BA1 5HY" on output. Line 4 was empty on input, and in populated on output. Address line 1 has also changed. The outer score is therefore quite low.