Thesaurus Leading Practices

When managing thesaurus rules, consider the following rules, behavior, recommendations, and tips:

  • A thesaurus entry is expanded for an exact match only (the stemming expansion is applied after the thesaurus expansion). Consider entering singular/plural, conjugation, one vs two-word, and other synonym variants to increase chances the entered keyword is expanded.

  • A specific keyword/expression can only appear once across thesaurus rules. You must group equivalent keywords/expressions in one thesaurus entry.

    Thesaurus rules are interpreted from top to bottom, meaning a rule containing a specific keyword/expression for the second time will be ignored.

  • Thesaurus rules are case insensitive, so do not bother entering casing variants.

  • The thesaurus is useful for example to match acronyms and abbreviations with their full versions, or jargon with proper terminology.

  • Identify searched keywords that do not return optimal results because users are not entering the indexed synonym keywords, and then create a thesaurus entry that expands the query to the appropriate synonyms.

  • Be careful to enter only legitimate synonyms to prevent excessive search result broadening that can negatively affect search results ranking and confuse users.

  • Avoid adding many thesaurus rules without a precise search optimization goal (for example based on an external glossary) to prevent adverse side effects that can confuse users.

  • Avoid using the thesaurus to expand a typo to its correct form. Based on the relative occurrences of a typo and its correct form in the index, the index Did You Mean feature will automatically correct or suggest the better spelling.

  • Immediately test your thesaurus entry creation or modification in the search interface to ensure that they improve search result relevance.

  • By default, the thesaurus entry expansion is omnidirectional or reciprocal to all keywords/expressions in the thesaurus entry, so be careful to not enter many synonyms in a given entry to prevent drastically increasing the length of the query.

    All thesaurus expanded query keywords are stemmed and expanded to other shared-root keywords, further increasing the length of the query.

  • Thesaurus rules apply to:

  • Thesaurus rules do not apply to:

    • Field queries.
    • Keywords entered next to the NOT and NEAR operators.

What’s Next?

Add thesaurus rules to your query pipelines (see Adding and Managing Query Pipeline Thesaurus Rules).