Skip to main content
  • Subscribe by RSS
  • Ex Libris Knowledge Center

    Summon: Effect of Emphasizing a Search Term

    • Product: Summon

    How are search results affected if we use a weighting character and number (such as '^10') on a term in a Summon search query?

    (Note: this is an advanced search option. Summon's relevance ranking algorithm is designed to work best with basic search options, and 99% of search cases should not need this option. If search results need to be refined or improved, we recommend that you start with more basic search options, such as faceting, phrase searching and field searching.)
    Summon's relevance ranking algorithm assigns weights to search terms according to the importance of the terms, approximated by a logarithmically scaled inverse of the document frequency (i.e., the number of documents that contain a term) in the entire Central Discovery Index. As a result, infrequent/rare terms are weighted higher than frequent/common terms.
    The "^" operator allows the modifications of the relevance weights of search terms, phrases, fielded searches or Boolean expressions. The format is term^multiplier or expression^multiplier. For example, the multiplier of 2 doubles the original weight, and the multiplier of 0.5 halves the original weight. When the "^" operator is used with a multi-term phrase or expression, the multiplier is applied to all of the terms in the phrase or expression.
    • yoruba books^2
    • "american history"^1.5 introduction
    • (cats OR dogs)^5 AND raccoons
    • Title:jazz^0.5 Author:(Jamey Aebersold)^2

    Please note that the "^" operator cannot be used within double quotes (e.g., "cats^2 dogs"). In such cases, the "^" operator and the multiplier are interpreted literally as part of the term.

    • Date Created: 9-Feb-2014
    • Last Edited Date: 24-Mar-2017
    • Old Article Number: 8790
    • Was this article helpful?