Master Index Match Engine Matching Comparison Functions At a Glance (Understanding the Master Index Match Engine)

Understanding the Master Index Match Engine

Master Index Match Engine Matching Comparison Functions At a Glance

Match field comparison functions, or comparators, compare the values of a field in two records to determine whether the fields match. The fields are then assigned a matching weight based on the results of the comparison function. You can use several different types of comparison functions in the match configuration file to define how the Master Index Match Engine should match the fields in the match string. The Master Index Match Engine provides several options to use with each function. You can also define custom comparison functions. For more information, see Creating Custom Comparators for the Master Index Match Engine.

The following table summarizes each comparison function. A complete reference of the comparison functions and their parameters is included in Master Index Match Engine Comparison Functions and Options.

Note –

The names of these comparison functions are configurable. The following table lists their default names.

Table 2 Comparison Function Summary


Comparison Function	Name	Description
b1	Bigram Comparator	Compares two strings using an algorithm based on the Bigram algorithm. This function compares two strings using all combinations of two consecutive characters and returns the total number of combinations that are the same.
b2	Advanced Bigram Comparator	Compares two strings allowing for character transpositions. This function is similar to the standard Bigram Comparator (b1).
u	Advanced Jaro String Comparator	Compares two strings taking into account uncertainty factors, such as string length, transpositions, and characters in common. This function is based on the Jaro algorithm.
ua	Winkler-Jaro String Comparator	Compares two strings similar to the Advanced Jaro String Comparator (u), but increases the agreement weight if the initial characters of each string are exact matches. This function takes into account key punch and visual memory errors. It is based on the Jaro algorithm with variants of Winkler/Lynch and McLaughlin.
uf	Advanced Jaro Adjusted for First Names	Based on the generic string comparator (u), this function is designed to specifically weight first name values. The string is analyzed and the weight adjusted based on statistical data.
ul	Advanced Jaro Adjusted for Last Names	Based on the generic string comparator (u), this function is designed to specifically weight last name values. The string is analyzed and the weight adjusted based on statistical data.
un	Advanced Jaro Adjusted for House Numbers	Based on the generic string comparator (u), this function is designed to specifically weight house number values. The string is analyzed and the weight adjusted based on statistical data.
us	Condensed String Comparator	Compares two strings similar to the Advanced Jaro String Comparator (u), but this function is a custom string comparator that compares two strings taking into account such uncertainty factors as string length, transpositions, key punch errors, and visual memory errors. Unlike the Advanced Jaro String Comparator, this function handles diacritical marks. This function also improves processing speed.
usu	Unicode String Comparator	Compares two strings similar to the Condensed String Comparator (us), but this function is based in Unicode to support multiple languages and alphabets. This comparator takes one parameter indicating the language to use.
usus	Unicode AlphaNumeric Comparator	Compares two strings similar to the Unicode String Comparator, but this function is designed to match on unique identifiers such as national IDs. This comparator takes one parameter indicating the language to use plus any of the following parameters: Field length Character types Invalid values
ujs	Advanced Jaro AlphaNumeric Comparator	Compares two strings similar to the Advanced Jaro String Comparator, but this function is designed to match on unique identifiers such as national IDs. This comparator takes any of the following parameters: Field length Character types Invalid values
c	Exact Character-to-Character Comparator	Compares string fields character by character. Each character must match in order for an agreement weight to be assigned.
nI	Integer Comparator	Compares integer fields using a relative distance value to determine the match weight. As the difference between the two fields increases, the match weight decreases. Once the difference is beyond the relative distance, a disagreement weight is assigned. This comparator takes two parameters; the first indicates whether to use a relative distance or direct string comparison and the second indicates the relative distance to use.
nR	Real Number Comparator	Compares fields containing real numbers using a relative distance value to determine the match weight. As the difference between the two fields increases, the match weight decreases. Once the difference is beyond the relative distance, a disagreement weight is assigned. This comparator takes two parameters; the first indicates whether to use a relative distance or direct string comparison, and the second indicates the relative distance to use.
nS	Condensed AlphaNumeric SSN Comparator	Compares social security numbers or other unique identifiers, taking into account any of these parameters: Field length Character types Invalid values
dY	Date Comparator With Years as Units	Compares year values using relative distance values prior to and following the given year to determine the match weight. As the difference between the two fields increases, the match weight decreases. Once the difference is beyond the relative distance, a disagreement weight is assigned. The date comparison functions handle Gregorian years. This comparator takes up to three parameters; the first indicates whether to use a relative distance or direct string comparison, and the second and third indicate the relative distance before and after.
dM	Date Comparator With Months as Units	Compares the month and year using a relative distance as described above for the year comparison function (dY).
dD	Date Comparator With Days as Units	Compares the day, month, and year using a relative distance as described above for the year comparison function (dY).
dH	Date Comparator With Hours as Units	Compares the hour, day, month, and year using a relative distance as described above for the year comparison function (dY).
dm	Date Comparator With Minutes as Units	Compares the minute, hour, day, month, and year using a relative distance as described above for the year comparison function (dY).
ds	Date Comparator With Seconds as Units	Compares the second, minute, hour, day, month, and year using a relative distance as described above for the year comparison function (dY).
p	Prorated Comparator	Prorates the disagreement weight for a date or numeric field based on values you specify. Differences greater than the amount you specify receive the full disagreement weight. This comparator takes three parameters indicating the relative distance and the agreement and disagreement ranges.