OpenURL
Encyclopedia
OpenURL is a standardized format of Uniform Resource Locator
(URL) intended to enable Internet users to more easily find a copy of a resource that they are allowed to access. Although OpenURL can be used with any kind of resource on the Internet, it is most heavily used by libraries to help connect patrons to subscription
content.
The OpenURL standard is designed to enable linking from information resources such as abstracting and indexing databases (sources) to library
services (targets), such as academic journals, whether online or in printed or other formats. The linking is mediated by "link resolvers", or "link-servers", which parse the elements of an OpenURL and provide links to appropriate targets available through a library by the use of an OpenURL knowledge base
.
The source that generates an OpenURL is typically a bibliographic
citation
or bibliographic record in a database that indexes the information resources often found in libraries, such as articles, books, patents, etc. Examples of such databases include Ovid
, Web of Science
, SciFinder, Modern Languages Association Bibliography
and Google Scholar
.
A target is a resource or service that helps satisfy a user's information needs. Examples of targets include full-text repositories, online journals, online library catalogs and other Web resources and services.
The National Information Standards Organization
(NISO) has developed OpenURL and its data container (the ContextObject) as American National Standards Institute
(ANSI) standard Z39.88. On 22 June 2006, the Online Computer Library Center (OCLC) was named the maintenance agency for the standard.
For example, changing either the base URL or a parameter in the query string can mean that the OpenURL resolves to a copy of a resource in a different library. So the same OpenURL, contained for instance in an electronic journal, can be adjusted by any library to provide access to their own copy of the resource, without completely overwriting the journal's hyperlink. The journal provider, in turn, is no longer required to provide a different version of the journal, with different hyperlinks, for each subscribing library. See also COinS
.
, which contains the address of the user's institutional link-server, followed by a query string
, which contains contextual data, typically in the form of key-value pairs. The contextual data is most often bibliographic data, but as of version 1.0 OpenURL can also include information about the requester, the resource containing the hyperlink
, the type of service required, and so forth. For example:
is a version 0.1 OpenURL describing a book.
A breakdown of the query string above shows that the following values are set:
, a librarian at the University of Ghent, in the late 1990s. His link-server software, SFX
, was purchased by the library automation company Ex Libris Ltd. which popularized OpenURL in the information industry.
In 2006 a research report found some problems affecting the efficiency of OpenURL linking and recommended the creation of a group to establish best practice solutions. The KBART (Knowledge Bases And Related Tools) working group has been set up to progress the recommendations of the research report.
(360 Link, formerly known as Article Linker), Innovative Interfaces, Inc. (WebBridge), EBSCO (LinkSource), Ovid
(LinkSolver), SirsiDynix (Resolver), Fretwell-Downing (OL2), TDNet (TOUR), WT Cox Subscriptions (Journal Finder), R.R. Bowker (Ulrichs Resource Linker) and Infor (Vlink). Open-source link resolvers include CUFTS and Umlaut. There are also open-source tools for manipulating OpenURLs and the Code4Lib community maintains a list of these.
OpenURL is usually implemented by information providers by dynamically inserting an appropriate base URL into web pages sent to an authenticated user. OpenURL COinS
is a specification that allows free services like Wikipedia
to provide OpenURLs by cooperating with client side software agents. Federated search
software presents OpenURL links in record fields by employing the library's subscriber links to link servers facilitating access to full-text resources from bibliographic record hyperlinks.
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
(URL) intended to enable Internet users to more easily find a copy of a resource that they are allowed to access. Although OpenURL can be used with any kind of resource on the Internet, it is most heavily used by libraries to help connect patrons to subscription
Subscription business model
The subscription business model is a business model where a customer must pay a subscription price to have access to the product/service. The model was pioneered by magazines and newspapers, but is now used by many businesses and websites....
content.
The OpenURL standard is designed to enable linking from information resources such as abstracting and indexing databases (sources) to library
Library
In a traditional sense, a library is a large collection of books, and can refer to the place in which the collection is housed. Today, the term can refer to any collection, including digital sources, resources, and services...
services (targets), such as academic journals, whether online or in printed or other formats. The linking is mediated by "link resolvers", or "link-servers", which parse the elements of an OpenURL and provide links to appropriate targets available through a library by the use of an OpenURL knowledge base
OpenURL knowledge base
An OpenURL knowledge base is an extensive database containing information about electronic resources such as electronic journals or ebooks and their availability and accessibility...
.
The source that generates an OpenURL is typically a bibliographic
Bibliography
Bibliography , as a practice, is the academic study of books as physical, cultural objects; in this sense, it is also known as bibliology...
citation
Citation
Broadly, a citation is a reference to a published or unpublished source . More precisely, a citation is an abbreviated alphanumeric expression Broadly, a citation is a reference to a published or unpublished source (not always the original source). More precisely, a citation is an abbreviated...
or bibliographic record in a database that indexes the information resources often found in libraries, such as articles, books, patents, etc. Examples of such databases include Ovid
Ovid Technologies
Ovid Technologies, Inc. , part of the Wolters Kluwer group of companies, provides access to online bibliographic databases, journals and other products, chiefly in the area of health sciences...
, Web of Science
Web of Science
ISI Web of Knowledge is an academic citation indexing and search service, which is combined with web linking and provided by Thomson Reuters. Web of Knowledge coverage encompasses the sciences, social sciences, arts and humanities. It provides bibliographic content and the tools to access, analyze,...
, SciFinder, Modern Languages Association Bibliography
Modern Language Association
The Modern Language Association of America is the principal professional association in the United States for scholars of language and literature...
and Google Scholar
Google Scholar
Google Scholar is a freely accessible web search engine that indexes the full text of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes most peer-reviewed online journals of Europe and America's largest...
.
A target is a resource or service that helps satisfy a user's information needs. Examples of targets include full-text repositories, online journals, online library catalogs and other Web resources and services.
The National Information Standards Organization
National Information Standards Organization
The National Information Standards Organization is a United States non-profit standards organization that develops, maintains and publishes technical standards related to publishing, bibliographic and library applications. It was founded in 1939, incorporated as a not-for-profit education...
(NISO) has developed OpenURL and its data container (the ContextObject) as American National Standards Institute
American National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
(ANSI) standard Z39.88. On 22 June 2006, the Online Computer Library Center (OCLC) was named the maintenance agency for the standard.
Use
The most common application of OpenURL is to assist in the resolution of a request for a web resource (such as an online article). An OpenURL includes information about the referenced resource itself, and context information — both the context in which the OpenURL occurs (for example, a page of search results from a library catalog) and the context of the request (for example, the particular user making the request). If a different context is expressed in the URL, a different copy ends up resolved to. Changes in context are predictable, and do not require the original creator of the hyperlink (for example, the journal publisher) to handcraft different URLs for different contexts.For example, changing either the base URL or a parameter in the query string can mean that the OpenURL resolves to a copy of a resource in a different library. So the same OpenURL, contained for instance in an electronic journal, can be adjusted by any library to provide access to their own copy of the resource, without completely overwriting the journal's hyperlink. The journal provider, in turn, is no longer required to provide a different version of the journal, with different hyperlinks, for each subscribing library. See also COinS
COinS
ContextObjects in Spans, commonly abbreviated COinS, is a method to embed bibliographic metadata in the HTML code of web pages. This allows bibliographic software to publish machine-readable bibliographic items and client reference management software to retrieve bibliographic metadata. The...
.
Format
An OpenURL consists of a base URLUniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
, which contains the address of the user's institutional link-server, followed by a query string
Query string
In World Wide Web, a query string is the part of a Uniform Resource Locator that contains data to be passed to web applications such as CGI programs....
, which contains contextual data, typically in the form of key-value pairs. The contextual data is most often bibliographic data, but as of version 1.0 OpenURL can also include information about the requester, the resource containing the hyperlink
Hyperlink
In computing, a hyperlink is a reference to data that the reader can directly follow, or that is followed automatically. A hyperlink points to a whole document or to a specific element within a document. Hypertext is text with hyperlinks...
, the type of service required, and so forth. For example:
http://resolver.example.edu/cgi?genre=book&isbn=0836218310&title=The+Far+Side+Gallery+3
is a version 0.1 OpenURL describing a book.
http://resolver.example.edu/cgi http://resolver.example.edu/cgi?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:book&rft.isbn=0836218310&rft.btitle=The+Far+Side+Gallery+3
A breakdown of the query string above shows that the following values are set:
- The URL version
url_ver = Z39.88-2004 - Custom metadata
rft_val_fmt = info:ofi/fmt:kev:mtx:book - And an object named "rft" is set which could be represented as
rft = { isbn:"0836218310", btitle:"The Far Side Gallery 3" }
History
OpenURL was created by Herbert Van de SompelHerbert van de Sompel
Herbert Van de Sompel is a Belgian librarian and computer scientist, most known for his role in the development of the Open Archives Initiative and standards such as OpenURL, Object Reuse and Exchange, and the OAI Protocol for Metadata Harvesting....
, a librarian at the University of Ghent, in the late 1990s. His link-server software, SFX
SFX (software)
SFX was the first OpenURL link resolver or link server. It remains the most widely-used OpenURL resolver, being used by over 1,500 libraries.Librarians Herbert van de Sompel, Patrick Hochstenbach and their colleagues at Ghent University in Belgium developed the OpenURL framework from 1998 to 2000....
, was purchased by the library automation company Ex Libris Ltd. which popularized OpenURL in the information industry.
In 2006 a research report found some problems affecting the efficiency of OpenURL linking and recommended the creation of a group to establish best practice solutions. The KBART (Knowledge Bases And Related Tools) working group has been set up to progress the recommendations of the research report.
Applications and tools
Several companies market link server systems, including OCLC (WorldCat Link Manager), Swets (SwetsWise Linker), Serials SolutionsSerials Solutions
Serials Solutions is a division of ProQuest that provides e-resource access and management services to libraries. These products enable librarians to more easily manage electronic resources that serve the needs of their patrons.-History:...
(360 Link, formerly known as Article Linker), Innovative Interfaces, Inc. (WebBridge), EBSCO (LinkSource), Ovid
Ovid Technologies
Ovid Technologies, Inc. , part of the Wolters Kluwer group of companies, provides access to online bibliographic databases, journals and other products, chiefly in the area of health sciences...
(LinkSolver), SirsiDynix (Resolver), Fretwell-Downing (OL2), TDNet (TOUR), WT Cox Subscriptions (Journal Finder), R.R. Bowker (Ulrichs Resource Linker) and Infor (Vlink). Open-source link resolvers include CUFTS and Umlaut. There are also open-source tools for manipulating OpenURLs and the Code4Lib community maintains a list of these.
OpenURL is usually implemented by information providers by dynamically inserting an appropriate base URL into web pages sent to an authenticated user. OpenURL COinS
COinS
ContextObjects in Spans, commonly abbreviated COinS, is a method to embed bibliographic metadata in the HTML code of web pages. This allows bibliographic software to publish machine-readable bibliographic items and client reference management software to retrieve bibliographic metadata. The...
is a specification that allows free services like Wikipedia
Wikipedia
Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its 20 million articles have been written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone with access to the site,...
to provide OpenURLs by cooperating with client side software agents. Federated search
Federated search
Federated search is an information retrieval technology that allows the simultaneous search of multiple searchable resources. A user makes a single query request which is distributed to the search engines participating in the federation...
software presents OpenURL links in record fields by employing the library's subscriber links to link servers facilitating access to full-text resources from bibliographic record hyperlinks.
External links
- ANSI/NISO Z39.88-2004 The OpenURL Framework for Context-Sensitive Services at NISO
- OpenURL standardization committee - archives of OPENURL@OCLC.ORG mailing list
- openurl.code4lib.org
- OpenURLs COinS