The SYNONYM Operator

The SYNONYM operator allows you to specify synonyms in the Query action Text parameter.

In this operator, you specify a list of synonymous words and phrases. The IDOL Content component treats the terms in the operator as individual query terms, separated by Boolean OR operators (that is, results can contain any of the listed terms).

For query weighting, Content scores all the terms in the SYNONYM operator as if they were a single term. This approach means that results that contain only one of the synonymous terms do not necessarily have a lower relevance score than one that contains more of the synonyms.

For example:

http://localhost:9010/action=Query&Text=SYNONYM(cat moggy kitten mouser) NEAR sale

The effective query text is (cat OR moggy OR kitten OR mouser) NEAR sale. However, if you use this query text without the SYNONYM operator, a document that contains the phrase cat sale twice scores lower than a document that contains the phrases cat sale and kitten sale, because it contains fewer of the query terms. With the SYNONYM operator, these documents score the same.

You can use quotation marks to define a synonym phrase. For example:

SYNONYM(dog labrador "golden retriever")

You cannot use the SYNONYM operator in an exact phrase search, for example, to match an exact phrase where one of the terms has several synonyms. In this case, you can use the NEAR operator to approximate the exact phrase search.

The SYNONYM operator is not the same as configuring a synonym list, because it does not affect how Content stores the documents in the index.

You can use the SYNONYM operator in combination with Query Manipulation Server, or a Synonym server. In both cases, you store the details of your synonyms in the external server, and replace the term in the query text with the SYNONYM operator and the list of synonyms.

For details about how to use synonyms in Query Manipulation Server, refer to the Query Manipulation Server Administration Guide. For details about using the Synonym Content Component, see Set up a Synonym Server.