What is in the WorldCat Discovery central index?
The central index is an index of metadata for a wide range of databases, articles, e-books, and digital materials libraries provide to their users, including materials from well-known content providers and open access resources. The central index:
- Represents 3,108 e-resource content collections from OCLC content partners such as EBSCO*, ProQuest, Gale, Springer and many others.
- Includes databases of the former FirstSearch Base Package (Electronic Books, ArchiveGrid, ArticleFirst, CAMIO Catalog of Art Museum Images Online, OCLC FirstSearch Electronic Collections Online Abstract & Index, OAIster, PapersFirst, ProceedingsFirst, WorldCat Dissertations and Theses, ERIC, GPO Monthly Catalog and MEDLINE). These databases can be selected and searched individually.
4,308,748,969 records are currently searchable through WorldCat Discovery.
As you view the list of collections included in the central index at http://oc.lc/indexDiscovery, note that the collections noted as "Complete" are those for which OCLC and the content provider have negotiated an agreement to surface this metadata through WorldCat Discovery. Collections noted as "Majority" are those for which WorldCat Discovery Services contains some metadata for 75 percent or more of the ISSNs or ISBNs indexed in the database or collection from another source.
What is the difference between the electronic content represented in WorldCat and the electronic content represented in the central index?
Metadata for electronic resources such as websites, e-journals and e-books has been added to WorldCat for many years. Some of the metadata has been contributed by OCLC member libraries and some has been added through OCLC partnerships with leading publishers and content aggregators.
The central index in WorldCat Discovery includes metadata from e-content collections often provided by libraries.
What is the difference between the central index for WorldCat Discovery and the WorldCat knowledge base?
The central index for WorldCat Discovery and the WorldCat knowledge base are complementary tools that enable information seekers to find and connect to information resources provided by libraries.
The WorldCat knowledge base contains detailed information about library holdings that enables linking from citations to full text in resources to which a library subscribes.
The central index in WorldCat Discovery is a rich index of metadata that provides unified access to a broad range of content, including the following resources:
- The WorldCat database of 510 million bibliographic records, representing the collections of thousands of libraries worldwide
- FirstSearch Base Package subscription databases (except Clase and Periodica)
- More than 200 million article-level records from sources that include HathiTrust, ArticleFirst, MEDLINE, ERIC, British Library Inside Serials, JSTOR, OAIster, Elsevier metadata and others
- E-resource collections from OCLC content partners such as ProQuest, Gale and others.
Metadata in the central index enables discovery, and library holdings data in the knowledge base facilitates links from citations to full text.
Does my library need to subscribe to collections represented in the central index in order to take advantage of search access through WorldCat Discovery?
The central index for WorldCat Discovery serves as a finding tool for millions of content items.
- Metadata for some of this content is searchable without a subscription.
- Some content collections are searchable without a subscription but require a subscription for access to full text.
- Other content collections require a subscription to search as well as display full text; when your library also subscribes to these content collections, you can use the built-in link resolution functionality provided by the WorldCat knowledge base or another knowledge base already in use at your library to connect users to full text.
An Excel file list of content collections in the central index is available, as well as PDFs for Complete Collections List, Open Access Collections List, Full-Text Searchable Collections List, Remote Database List, and Collections that Require Authentication to Search List.
Does WorldCat Discovery favor specific content sources in search results?
No. WorldCat Discovery is a content-neutral service. The WorldCat Discovery central index represents collections from a broad range of authoritative content providers, and search algorithms do not favor specific content collections.
What is the relationship between searches of the central index for WorldCat Discovery and searching remote databases not represented in the central index?
The central index is available for searching by users of all FirstSearch/WorldCat Discovery subscribers. Searches retrieve results from WorldCat and the central index. The e-content that a library makes available to its users depends on its subscriptions to e-content collections.
Remote database searching lets libraries also include searches of metadata not included in the central index for WorldCat Discovery as part of users' search experience. Recommended remote databases from EBSCO and ProQuest that are not included in the WorldCat Discovery central index display at the top of search results with an indication of the approximate number of results expected from each. Users can click on a recommended database to connect to the database's native interface to continue searching.
How do libraries begin to use the WorldCat knowledge base?
Use of the WorldCat knowledge base is included in an OCLC Cataloging and Metadata Subscription. To use the WorldCat knowledge base, complete a knowledge base request form, add data about electronic collections to the knowledge base and activate the functionality. Methods for adding a library's local data to the WorldCat knowledge base are described in Building your WorldCat knowledge base: Choose a method to add your collections (PDF).
