The Synonym Detection feature generates pairs of synonyms and pairs of similar queries. Two words are considered potential synonyms when they are used in a similar context in similar queries. When synonym detection is enabled, a query that contains a matching term is expanded to include all of its synonyms, with the original term boosted by a factor of two.
Synonyms are applied in the Text Tagger stage of the query pipeline.
The Synonym and Similar Queries Detection job automatically creates synonym pairs based on your AI-generated data. When you navigate to Relevance > Query Rewriting > Synonym Detection, you can review or edit the output from the job and manually add new synonym pairs. Your changes remain in the _query_rewrite_staging collection until you publish them.
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When you manually add new synonym pairs, subsequent job runs use those documents as input for machine learning to improve the job’s output. Unlike job-generated documents, manually-added query rewriting documents are never overwritten by new job output. |
To learn how to use synonym detection in the Rules Editor, see Use Query Rewrites in the Rules Editor.
Synonym directionality
When you edit or create a synonym pair, you can configure its directionality, either uni-directional or bi-directional.
To toggle between uni-directional and bi-directional, click the 
icon next to the synonym pair, then click the directionality icon:
Uni-directional synonyms
Uni-directional synonyms produce query substitutions. That is, when a query term matches a known uni-directional synonym, the original query term is replaced with the synonym.
In the uni-directional example below, "iphone" is a synonym of "phone" but "phone" is not a synonym of "iphone". When "phone" is found in a query, it is replaced with "iphone".
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When you manually create a new synonym pair, the default is uni-directional. |
Bi-directional synonyms
Bi-directional synonyms produce expanded queries. That is, when a query contains a known bi-directional synonym, the query is rewritten to include the original term plus all of its known bi-directional synonyms, resulting in a greater number of potentially relevant results. The original term is also boosted to help preserve the user’s intent.
In the bi-directional example below, "tv" is a synonym of "television" and "television" is a synonym of "tv". If a query contains either "tv" or "television", the query is expanded to include both terms.
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Job-generated synonyms are always bi-directional unless a reviewer edits them. |