WorldCat The World’s Largest Library Catalogue

Screenshot Worldcat
Screenshot Worldcat | Photo (detail): © WorldCat

WorldCat is the world’s largest library catalogue. This central database contains information about printed and digital publications in more than 470 languages. A portrait of an extraordinary research and cataloguing tool.

There are some things that actually grow while you watch, and WorldCat is one of them. On the website of the world’s largest library catalogue, it is possible to see how new data records are being added all the time – on average seven per second.

Containing 250 million data sets and over 1.7 billion holding records, WorldCat is the world’s largest database of bibliographic records of library and, increasingly, archive collections. This huge store of information contains knowledge from over 4,000 years, in more than 470 languages and in every conceivable format: books, magazines, eBooks, DVDs, digital resources, collections, anthologies, audio recordings, music scores, maps, photographic material, computer files and much more besides.

“No other source provides such a detailed overview of anything that has ever been published anywhere in the world”, notes Gabriele Messmer from the Bavarian State Library’s “Collection Development and Cataloguing” department.

Comprehensive research instrument

“WorldCat is a comprehensive research instrument for anyone searching for information”, explains Berndt Dugall. Johann Christian Senckenberg, director of the university library in Frankfurt am Main, is impressed not only by the large volume of information, but especially by the innovative range of applications: “Research via smartphone or tablet is offered as a matter of course, and it is also possible to link records to user-specific location information: this allows users to see whether the title they are looking for is available in a library close by.”

Use of WorldCat as purely a research tool is free of charge. “From WorldCat there are also links to full texts. One very useful research aid, for example, is the cooperation with Google. Through a link with Google books, WorldCat allows full text research in several million titles”, reports Andreas Kliemt from the Information department at Berlin’s Central and Regional Library.

Early days as regional library network in Ohio

What we now know as WorldCat was launched in August 1971 as the OCLC Online Union Catalog and Shared Cataloging System. At the time, 54 college and university libraries in the US state of Ohio wanted to combine their resources and save costs. OCLC stood for “Ohio College Library Center”.

What started over 40 years ago as a regional library network has evolved to become an international network today in which 10,000 libraries from 170 countries list their holdings. Behind WorldCat is the non-profit organization OCLC – which since 1981 has stood for “Online Computer Library Center”.

Huge visibility of holdings

OCLC is financed by its members, that is to say the libraries and other information institutions which participate in WorldCat. There are various cost models depending on which services are used. Active participation – contributing one’s own data, for instance, or using third-party catalogue data from WorldCat – requires payment of a fee.

It is clearly well worthwhile for libraries to make this financial investment, however, given the resulting huge global visibility of their own holdings – directly via and also in general search engines like Google, Yahoo! or Bing. Besides the German National Library, around 300 German libraries now list their titles and holdings in WorldCat; for the most part this is done via the country’s main library networks (GBV, HeBIS, BVB and SWB).

Participating libraries see the opportunity to include data from WorldCat in their local catalogues as a major advantage. “With its many additional functions, WorldCat is an important cataloguing tool for us. It is also very helpful when organizing interlibrary loans”, says Berndt Dugall. “Academic libraries certainly benefit from taking part. Its language diversity in particular makes WorldCat an excellent resource for third-party data.”

Problems with data formats and usage rights

One thing that many libraries in Germany still regard as an obstacle is that data have to be transferred to WorldCat in the MARC 21 format. This was not previously the standard format used for data exchange in Germany. “Increasingly, however, catalogue systems are now offering this MARC interface”, says Gabriele Messmer, one of the people responsible for coordinating the export of the Bavarian State Library’s catalogue data to WorldCat. The new “Resource Description and Access” (RDA) standard for cataloguing, to be introduced in many countries over the next few years, will greatly facilitate the exchange of data.

The “WorldCat Record Use Policy”, which regulates the use of catalogue data, has also been the target of criticism. “In my opinion, it is overly restrictive in today’s world”, explains Gabriele Messmer. “There should be no restrictions on the use of open catalogue data. That said, the guideline is being continuously revised and further developed by the members of OCLC.” WorldCat is growing regardless – growing, and growing, and growing.