Synonyms Dictionary

The Synonym Dictionary enables you to improve search results in the Knowledge Base by defining equivalent terms. This feature is used by the BM25 search algorithm to match user queries with relevant content, even when different wording is used.

The Synonyms Dictionary lets you group related words into synonym sets.

BM25 Search Logic

When a user searches for a term, the system also considers its synonyms when retrieving results. When the BM25 search uses the Synonyms Dictionary, a specific scoring weight is applied to ensure the most accurate results are prioritized. The system distinguishes between the original term used in the query and its defined synonyms:

  • Original term match: Sentences containing the exact word used in the user query receive a 100% matching score.
  • Synonym match: Sentences containing a synonym from the dictionary (instead of the original word) receive an 80% matching score.

This scoring ensures that while synonyms help expand the search reach, the engine still favors documents containing the user's specific vocabulary.

Add Synonym Sets

To manage the dictionary, navigate to NLU > Knowledge Base Settings > Advanced Settings.

  1. Locate the Synonym Sets accordion and expand it.
  2. Click the + (Add) icon to generate a new entry line.
  3. Enter the terms you wish to group together, ensuring each word or phrase is separated by a comma followed by a space (e.g., in stock, available, ready to ship, on hand).
    4. HINT: Ensure there are no trailing commas at the end of a set to maintain search index integrity.
  4. To save the set, press ENTER on your keyboard or click the + icon again to add a subsequent set.

Edit and Delete Synonym Sets

To edit a set, click on the specific line and make the desired changes.

To remove a synonym set from the dictionary, click the - (Minus) icon next to the row.

Best Practices

To maximize the effectiveness of the Synonyms Dictionary and ensure the BM25 search remains accurate, consider the following guidelines:

  • Focus on grouping industry-specific jargon, abbreviations, or common interchangeable terms to bridge the gap between user intent and KB content.
    • Copy
    Retail examples
    //Acronyms
    POS – Point of Sale
    AOV – Average Order Value
    ATV – Average Transaction Value
    UPT – Units per Transaction

    // Retail industry jargon
    cheap, affordable, budget-friendly, low-cost, economical
    expensive, premium, high-end, luxury, upscale
    discount, markdown, price cut, reduction, deal
    bargain, steal, value buy, great deal

    sale, promotion, offer, deal, special
    clearance, closeout, final sale, liquidation
    limited-time, flash sale, short-term offer, exclusive deal
    bundle, package deal, combo, set

    in stock, available, ready to ship, on hand
    out of stock, unavailable, sold out, backordered
    limited stock, low inventory, almost gone
  • Keep sets specific to avoid surfacing irrelevant documents. Because synonyms carry an 80% weight, adding too many broad terms to a single set can "dilute" search results.
  • Standardize Formatting. Always use the word, synonyms, phrase format. Avoid adding special characters or extra spaces within the terms themselves, as this can interfere with the search engine tokenization.
  • Monitor Search Performance. Periodically review the Knowledge Base Logs to identify "No Results Found" queries. Use these insights to expand your Synonym Sets with the terms your users actually use.