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variables with a low m-probability so there is a smaller penalty for
mismatches.
You will notice that a matching run on fewer variables will have
better match rates than those with more variables included. This
is because decreasing the number of variables that participate in a
match also decreases the discriminating ability to differentiate the
correct matches from the incorrect matches. For example,
matching a pair of files on the variable sex alone will match almost
all the records, but you would have no confidence that the
matches pertain to the same individuals on both files.
CNT_DIFF: Count number of chars difference
D_INT: Left/Right Intervals (DIME/TIGER)
DATE6: Date in the form of yymmdd
DATE8: Date in the form of yyyymmdd
DELTA_PER: Delta Percent
DISTANCE: Geometric distance
INTERVAL_NOPAR: Interval
INTERVAL_PARITY: Odd/Even Interval
The MATCH statements form the heart of a matching run. The
format of the MATCH statements may seem complex, but
basically they specify the type of comparisons to be made
(character, numeric, and so on), the fields involved in the
comparisons, and the m and u probabilities.
LR_CHAR: Left/Right character string comparison
MATCH statements are formatted according to the following:
PRORATED: Prorated
For matching single variables:
MATCH
<comparison-type>
<match key field>
<reference file variable name>
<m-probability>
<u-probability>
[<additional-parameters>]
[<mode>]
where:
<comparison-type> ::=
CHAR: Character
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LR_UNCERT: Left/Right uncertainty string comparison
NUMERIC: Numeric
PREFIX: Prefix character
TIME: Time
UNCERT: Uncertainty character comparisons
<additional-parameters>
a numeric value or value required for types UNCERT,
LR_UNCERT, PRORATED, TIME, and DELTA_PER.
<mode>: required for types INTERVAL_NO,
INTERVAL_PARITY, and D_INT:
ZERO_VALID: Zero is valid and may be part of interval
ZERO_NULL: Zero is null and never part of the interval
required for types LR_CHAR and LR_UNCERT:
EITHER: Match on either left or right side
BASED_PREV: Match on side based on results of previous left/
right interval compare
GEOCODING RULE BASE DEVELOPER GUIDE