Can apply to: Books
Metric definition: The number of libraries that own (“hold”) a book.
Metric calculation: Holdings counts are derived from national or international union library catalogues, such as OCLC WorldCat. The holdings count is calculated as the number of unique libraries that own a copy of a book.
Data sources: Library book holdings as represented in union catalogs.
Appropriate use cases: Books may produce benefits and impacts that aren’t well captured by conventional bibliometrics, such as citation counts. Monograph holdings can be used to demonstrate a book’s perceived potential to meet user, teaching, and research needs.
Limitations: Monograph holdings counts and contextual data, such as the type of libraries that own a book, do not reveal how, if and how often, and by whom a book is used. Research shows that the use of academic library collections is driven by a small percentage of content. Moreover, monograph holdings provide an incomplete understanding of historical impacts on such areas such as teaching as research, because less current materials are often weeded from library collections.
Inappropriate use cases: Monograph holdings should not be used as a direct measure of usage, research quality, or impact.
Transparency: In all of the sources in which monographs holdings data are available, one can trace the details of each library’s ownership information. Note that certain catalogs like WorldCat allow subscribing institutions to withhold their collection information from the public, meaning actual holdings aren’t always fully reflected in publicly-available catalogs.
Timeframe: Monograph holdings data can reflect current library book collections; books of any age that appear in a collection will be included.