Probable matches are determined by the algorithm described below.

There are 5 required fields in the search:

• SSN

• First name

• Last name

• DOB

• Gender

The are weighted as follows:

• 4 x SSN score

• 1 x First name score

• 2 x Last name score

• 1 x DOB score

• 1 x Gender score

The total possible score is 12. The system displays all results that have a score > 5.9.

SSN score:

Determined by a normalized Levenshtein distance score which is determined by the (longest string - the total number of transformations)/ the longest string. This will result in a score of between 0 and 1.

First name score:

There are two attributes to the name score. The first is a double metaphone search which will return true or false.  If true the score is 1, and if false the score is -1.  The second score is based on the normalized Levenshtein determination.

Last name score:

There are two attributes to the name score. The first is a double metaphone search which will return true or false.  If true the score is 1, and if false the score is -1. The second score is based on the normalized Levenshtein determination.

DOB score:

Exact Match = 1, within 30 days = 0.5, within 365 days = 0.2, mm/dd match = 0.2, mm/yy match = 0.2, No Data for the variable = 0, No Match = -1.

Gender score:

Match = 1, No Data for the variable = 0, No Match = -1.