Synonym Detection
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 > Rules, the application displays the Query Rewriting screen. Select Synonym Detection. The application displays the Synonym Detection screen.
To review, edit, or add synonyms, see Using Synonym Detection.
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.
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".
| 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.
| Job-generated synonyms are always bi-directional unless a reviewer edits them. |