Frequency

The Frequency (Freq) module provides result scoring based on the frequency (number of occurrences) of the user’s query terms in the result text.

Results with more occurrences of the user search terms are considered more relevant.

The score produced by the Frequency module for a result record is the sum of the frequencies of all user search terms in all fields (standard or managed attributes in the search interface in question) that match a sufficient number of terms. The number of terms depends on the match mode, such as all terms in a query with search mode All, a sufficient number of terms in a query with search mode Partial, and so on. Cross-field match records are assigned a score of zero. Total scores are capped at 1024; in other words, if the sum of frequencies of the user search terms in all matching fields is greater than or equal to 1024, the record gets a score of 1024 from the Freq module.

For example, suppose we have the following record: 
{Title="test record", Abstract="this is a test", Text="one test this is"}
An All search for test this would cause Frequency to assign a score of 4, since this and test occur a total of 4 times in the fields that match all search terms (Abstract and Text, in this case). The number of phrase occurrences (just one in the Text field) doesn't matter, only the sum of the individual word occurrences. Also note that the occurrence of test in the Title field does not contribute to the score, since that field did not match all of the terms.

An All search for one record would hit this record, assuming that cross field matching was enabled. But the record would get a score of zero from Freq, because no single field matches all of the terms. Freq ignores matches due to query expansion (that is, such matches are given a rank of 0).

Note: Due to performance issues, do not use the Frequency module with standalone relevance ranking (that is, per-query relevance ranking).