Pitney Bowes MapMarker USA - Manual (Page 119)

Chapter 5:
Choosing Match Strategies
MapMarker USA 25
119
User Guide
While this strategy likely yields false positives, this may be the best match solution when you have
large databases that need to be geocoded. You must decide if the percentage of false positives
affects your analysis.
L
You can evaluate false positives if you have MapMarker use output columns to store the
returned street, city, state, and ZIP Code values. See
Selecting Input and Output Address
Columns . Look for false positives by comparing the input address with the output address.
To further reduce the number of false positives without sacrificing hit rate, analyze the result codes
after a geocoding session and re-geocode interactively. See
Result Codes for more information on
result codes.
Maximizing Geographic Accuracy
If positional accuracy of the geocoded records is the most important aspect for you, choose a
strategy in which MapMarker returns the lowest number of erroneous matches. To do this, you must
require MapMarker to find exact matches for all portions of the address—house number, street
name, city, and ZIP Code™. Also, do not accept the first of multiple matches or fall back to ZIP
®
centroid. These records remain ungeocoded.
The strictest match settings require an exact match on house number, street name, city name, and
ZIP Code. In that case, MapMarker is looking for an exact street address match within the city and
ZIP Code named in your input address.
Choose this scenario when your analysis requires precise locations for your records. To increase the
number of matches, your next step might be to use interactive geocoding. Interactive geocoding is
explained in
Making the Most of Interactive Geocoding .
Balancing Match Rate and False Positives
You may want to use a balanced strategy between match rate and geographic accuracy. That is, you
may want to geocode as many records as possible automatically, but at the same time want to
minimize the number of erroneous matches (false positives). Rather than generate false positives,
you could leave those records ungeocoded so that you can geocode them interactively later. You
may want to analyze your data at a local level where the location of each record on a map is
important.
MapMarker may return false positives when it:
• finds a street that sounds like the input street.
• finds the same street in another town (if ZIP Code match is not specified).
• finds the street but with a different house number (if House Number is not specified).
MapMarker, however, contains a sophisticated matcher that usually finds the correct address.
MapMarker Standard mode achieves a balance of accurate geocoding, few false matches, and high
performance. Standard mode requires a close (not necessarily exact) street name match. You can
use other match modes or custom match settings to achieve the best match strategy for your data
and requirements.