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    Primo/Primo Central Searching and Search Results Evaluation

    • Product: Primo, Primo Central
    • Relevant for Installation Type: Dedicated-Direct, Direct, Local, Total Care



    How is search configured in Primo? What factors into the results?


    Searching in Primo 

    Though there are nearly endless possibilities for configuring what Primo searches, most sites offer end users the ability to search their local collection (E.g., “Books +”) or Primo Central (E.g., “Articles +”), or both (E.g., “Everything”). Talk with your local Primo administrator to make sure you know how your collections are presented for searching in your Primo interface.

    Primo Central 

    Primo Central is a mega-aggregation of hundreds of millions of scholarly e-resources (including journal articles, e-books, reviews, legal documents and more) that are harvested from primary and secondary publishers, aggregators, and open-access repositories.


    Your site can select which Primo Central collections are available for your users to search. (See Additional Resource section below for Primo Central Index Collection lists.)

    You can also decide to limit the default search to only those citations where full text is available for your users. In this case, users will still have an option in Primo to expand results to include citations where no full text is available.

    Local Collections 

    Local collections mainly include your library catalog – what you may think of as available via your OPAC - but may also include other local metadata or digital repositories managed by your library.


    When a user searches collections from both Primo Central and your local collection(s), we refer to these as blended results. Blended results bring together data from different sources, which often have their own search engines and ranking algorithms. In this case, Primo determines how to reconcile these into a single, ranked result list.

    Evaluating Search Results 

    Looking at search results from Primo, especially from a blended search, is very different from looking at search results from your traditional OPAC. Primo is often searching hundreds of millions of articles alongside your local collection. There are several factors that affect how a ranked list of blended search results is produced:

    • Relevance
      • For author and author/title searches, the weight of the original book was increased to ensure that it is ranked higher than material about the book.
      • When searching for author names, the weight of the material written by the author has been increased above the material about the author.
      • Greater weight is given if keywords are found in author, title or subject fields
        • Exact Title match is set to be weighted the most heavily
      • In a keyword search, a record is ranked higher if the term or phrase order is the same as in the record
      • Ranking also factors in how often the search terms occur in the record
    • Academic significance
      • Published in a peer reviewed journal
      • Number of times cited
      • Material type (i.e. journal article vs. newspaper article)
    • Type of search
      • If Primo interprets the keywords as a broad topic search, overview material will be higher in the results
      • If Primo interprets the keywords as a known-item search, author and exact title matches will be higher in the results (see “How Do Users Search and Discover” White Paper in Additional Resources below)
      • For citation searches, if a user pastes citation information into the search, Primo's search engine has been enhanced to recognize the author, title, and date better to find the item regardless of the extra metadata in the query. 
    • Publication date
      • More recently published Primo Central materials show up higher in the results list
      • Sites can configure whether or not publication dates affect the relevance of local collections
    Blending configuration 

    Primo Central records are often heavily weighted when blended results are ranked. To balance this and make sure users can access the most relevant local resources, libraries have the ability to influence how local results get blended into the first page of search results (often referred to as ‘boosting’). Check with your local administrator to see how blending is configured at your site.  

    Display streamlined for end users 

    We try to strike a balance of providing just enough information in the display for a user to make a decision about the usefulness of the item without overwhelming them with information. That means that, though indexed for searching, many metadata fields may not be configured to display.


    Keep in mind that:

    • A search looks across more data than just Title

    • You can check the Details tab for highlighted words in Title, Subject, or Author fields, which will show the display fields that matched your search terms
    • In some cases, your search term will be found in a field that is not configured to display at all
    Functionality designed to avoid too few results 

    In an effort to provide users with results that they can explore and refine, searches of Primo Central content automatically search the indexed full text. The ranking algorithm considers the full-text searching and gives relevance to results that are highly ranked from full-text searching. This behavior was updated in January 2017. As a result, users may see a substantially higher number of search results for many searches. This change also solved issues with discrepancies in the result count between searches with and without the use of Boolean "OR" and "NOT" operators.


    • Variations of the search terms (E.g., cultur*) will be included in the search
      • Note: If found, the exact matches for the search terms are weighted more highly than the variations

    Additional Information 

    Learn more about Primo Search and Ranking:

    Learn more about Boolean operators, wildcards, and more in Primo:


    Primo Central Indexing: Lists


    • Article last edited: 22-Jun-2016