Accuracy of commercial geocoding: assessment and implications

Table 2 Characteristics of the four vendors

Vendor	CASS	Street Offset	Corner Inset	Street Data Files			Scheduled Data File Updates	Original Datum^a	Manual Address Cleaning^b
				TIGER	USPS	Other
A	Yes	40 ft	Yes	2002	2004	Yes	4×/yr	WGS84	No
B	No	5 ft	Yes	2002	2004	Yes	4×/yr	NAD83	No
C	Yes	50 ft	No	2002	2004	Yes	6×/yr	NAD83	Yes
D	No	0 ft	No	2002	2003	No	2×/yr	NAD83	No

^aOf assigned coordinates: NAD83 = North American Datum of 1983. WGS84 = World Geodetic System of 1984. ^bAfter initial processing by geocoding software. CASS = Address standardization certified by the United States Postal Service National Customer Support Center Certification Program, Coding Accuracy Support System. TIGER = Topologically Integrated Geographic Encoding and Referencing (TIGER/Line^®) file. USPS = United States Postal Service files e.g. the city-state, ZIP+4^® and ZIPMove products.