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    Summon: Origin of Summon Records, and Match and Merge

    • Product: Summon

    Where do the records in the Summon service come from, and how are they combined with other records to form the Summon Index?

    The Summon service obtain citations and content from a variety of providers, including over 7,000 publishers and over 100,000 journal and periodical titles. Using our Match and Merge system, multiple records for the same item are combined into a single Summon service record. We currently map to over 80 different content types and regularly review and add more content types as content diversifies.

    Our metadata librarians work directly with publishers to secure the best possible metadata for each item, then merge metadata elements to create superior records. We provide full-text indexing for better discovery, and we index and preserve subject terms from the source materials indexed. In addition, we provide value-add features such as journal authority information, authoritative Ulrich's peer-review data, and Web of Science citation counts -- all to create a single, rich, Summon record.

    What about a print book sitting on your library shelf and also available as an e-book? The match and merge functions are intended to match individual catalog records for the same item and merge them together. All three of the following conditions must match before we merge your catalog record with other Summon records:

    1. ID: At least one of the following unique identification numbers must match:

      ISBN to ISBN
      EISBN to EISBN
      ISSN to ISSN
      EISSN to EISSN
      OCLC to OCLC
      LCCN to LCCN

    2. Publication date year: The year must match within +/- one year and the record must have only one publication year.

    3. Title: There must be a legitimate title-match. (We use fuzzy logic for title matching to overcome normal title variations such as "&" versus "and".)

    Government-document records do not merge with book or e-book records.

    In addition, Match and Merge logic for ebooks prevents separate records from merging into a single result if the difference in their publication dates is greater than three years. For example, if setting a facet of 2014 - Present, you should not see book citations from the 1990s, though you might see some citations from 2012 or 2013. Three years' difference allows for slight variations in publication dates given to ebooks by different publishers so that the occurrence of duplicate results can be minimized.

    Here is a visual representation showing key elements of the merge process:

    Match and Merge system

    On your Summon results page or link-resolver results page, you can see where a citation is available in your library's holdings; however, we may have acquired the citation from sources other than your subscriptions.

    Content in the Summon Index is updated on a schedule appropriate to the content. Library catalog updates and newspaper sources are added nightly. Journal-article sources may update weekly, bi-weekly, monthly, or quarterly, depending on the frequency of publication. Note that when you first add a new resource to your Client Center profile, it takes about 48 hours for the Summon Index to recognize your new subscription.

    Significant increases in the size of the Summon Index are currently allowing for index updates to occur twice a week. Work is being done to be able to return to nightly updates for content such as daily newspapers. The status of the Summon Index can be reviewed in the Summon Index Update.

    • Date Created: 9-Feb-2014

    • Last Edited Date: 19-July-2019

    • Old Article Number: 8824