Pitney Bowes MapXtreme - Manual (Page 339)

Chapter 18: Geocoding
Understanding Accuracy for Close Matches
MapXtreme v7.1 346 Developer Guide
component that supports CASS in order to use CASS geocoding. Contact your MapInfo sales
representative to obtain a current version in order to comply with CASS address standardization.
The default is false.
Impact of Relaxing Match Constraints
Relaxing the conditions broaden the area in which it searches for a match. For example, by relaxing
the postal code, a search will be performed for candidates outside the postal code but within the city
of your input address. Consider the following when you are determining the settings for geocoding:
Relaxing Postal Codes
When postal codes are relaxed, a search is performed on a wider area for a match. While this results
in slower performance, the match rate is higher because the request does not need to match exactly
when it compares match candidates.
Relaxing Subdivisions and Municipalities
When these are relaxed, a search is performed on the street address matched to the particular
postal code, and considers other cities or subdivisions that do not match the name, but do match the
postal code.
Relaxing Street Name
A search is performed that looks at all candidates with names that sound like the input address or
that are spelled improperly. This slows down the performance. On the plus side, since more
candidates are examined, the match rate increases. If your table is indexed, the time difference
between performance and match rate is reduced.
Relaxing House Number
Performance is not significantly affected when the house number setting is relaxed. It does,
however, affect the type of match if the candidate address corresponds to a segment that does not
contain any ranges. The type of match can also be affected when the house number range for a
candidate does not contain the input house number. If you are relaxing the house number, it is
recommended that you set the maximum ranges to be returned to a value higher than 0.
Understanding Accuracy for Close Matches
The ranking of the results is based on the close match of the request. For the GeocodeMatchCode
class, the geocoding server or service returns a result code for every record it attempts to match
based on the combination of GeocodeConstraints in the request and server or service configuration.
The code represents the success or failure of the geocoding operation and conveys information
about the quality of the match. The codes fall into five major categories:
• Single Close Match (S Category)
• Best Match from Multiple Candidates (M Category)
• Postal Code Centroid Matches (Z Category)