SFX: Open Linking for Libraries

Citation

Walker, J. (2001), "SFX: Open Linking for Libraries", Library Hi Tech News, Vol. 18 No. 3. https://doi.org/10.1108/lhtn.2001.23918caf.002

SFX: Open Linking for Libraries

Jenny Walker

Linking is an all-pervasive activity in the Web environment of today, and users of scholarly information resources expect the same level of interconnectivity in their research environments. Universal access to information, and desktop delivery of this information are now considered key services ­ absolute necessities in many institutions rather than just desirable features. But how, in an electronic environment, can you create that serendipity of old where, by browsing the stacks, you discover other related and relevant resources? Or provide the associative indexing suggested in the groundbreaking 1945 paper by Vannevar Bush "As we may think"?

An answer lies in SFX. In its very name, SFX ­ Special Effects, is suggested some of the magic that this holds.

The SFX Server

SFX, from Ex Libris, is an independent link server for libraries that manages the links between resources in a library's electronic collection. Such links are entirely under the control of the librarian both in terms of what types of links are presented to the user and to where such links should resolve, thereby addressing the "appropriate copy" problem. A link to full-text should lead, not to the default copy, but rather to the institutional copy of a paper, in electronic form and/or in print form. SFX permits context-sensitive linking among all parts of a library's electronic collection, including full-text repositories; abstracting, indexing, and citation databases; online catalogs (OPACs); and citations appearing in research articles, e-print systems, and other Web resources (see Figure 1).

Figure 1. The SFX server permits linking among all parts of a library's electronic collection

Users whose institutions have an SFX server will notice as they navigate resources ­ hosted locally by the institution or remotely by third parties ­ that an SFX button appears along with each retrieved reference. Clicking on the SFX button for a reference brings up an SFX menu window from which the user can select from a number of services that are relevant for that reference. These services are institution-specific and will lead users only to those resources and services deemed appropriate by their librarian. The librarian can determine the scope, definition and description of such services to be offered based on the information resource from which the user is linking, and on the content of the reference. SFX services will only be offered for a particular request if the target service is deemed to be able to resolve such a request. For example a link to the electronic full text of an article will only be offered as a service to the user if:

the article is known to be published in electronic form; and

the user's institution has a valid subscription to the relevant journal issue.

SFX extends the linking concept well beyond that of linking to the full-text of an article. Whilst the delivery of full-text to the desktop has been a major advance in recent years and offers a key service to researchers, with SFX the librarian can define many additional services they consider relevant to their users. These may include:

links to the OPAC to check local holdings details and status;

links to a preferred document delivery supplier;

links to check the author, article and/or journal citation information;

links to local information repositories;

links to relevant Web-based resources, possibly via the emerging subject gateways;

... and many more.

Librarians managing an SFX system are the first to be in the "trail blazers" profession, predicted by Vannevar Bush: they find delight in the task of establishing useful links between resources.

SFX and the OpenURL

The SFX "magic" cannot, however, occur without the cooperation of Information Service Providers who must enable their systems to work in an open linking environment. The underlying mechanism that allows an information resource to be the starting point of SFX links is the OpenURL: an interoperability specification that enables an SFX server to actually provide links for references that appear in heterogeneous distributed resources (see Figure 2). In the OpenURL, a reference is described in a standardized way by means of metadata and/or identifiers.

Figure 2. The SFX User Workflow ­ from an SFX Source (OpenURL-enabled resource) via an SFX Services Menu to an SFX Target

The OpenURL has been submitted to NISO for accreditation as an ANSI Standard; and has been accepted as a Fast Track work item. A growing number of Information Providers have developed or announced the ability to generate and output OpenURLs, and therefore their services will interoperate with an institutional SFX server. A list of these Providers can be found at: http://www.sfxit.com/sources.html. The current draft specification of the OpenURL and other relevant material relating to the OpenURL can be found at: http://www.sfxit.com/OpenURL.html

SFX and OpenURL derive from research work by Herbert Van de Sompel and his team at Ghent University Library in Belgium. This research work centered on the problem of linking ­ under control of the library ­ between heterogeneous information resources of the Ghent electronic collection, comprised both locally and remotely hosted resources. In early 2000 Ex Libris acquired the SFX technology from Ghent University.

Implementing SFX

SFX servers are already installed and operational at a number of institutions, both in the USA and in Europe. One such institution is the Los Alamos National Laboratory. Many readers will have attended the LITA session at the recent ALA Midwinter meeting in DC, where Miriam Blake of the Los Alamos Research Library gave an excellent and comprehensive presentation of their implementation of SFX. Her presentation can be found at http://lib-www.lanl.gov/lww/add.htm

Experience to date from SFX sites, suggests that fairly minimal staff resource is required to maintain an SFX server, in particular to manage the underlying SFX database that describes an institution's e-collection. Importantly, the resources that are required are an effective re-allocation of existing resources and not an additional resource. Ex Libris provides templates that facilitate customization to a library's local environment. Efforts are underway to enable integration with third party subscription services to further streamline the ongoing maintenance activity. Librarians can do the majority of the work, with computer-technical staff required only for specific tasks such as integration of SFX with local data repositories.

Benefits for Libraries

SFX provides extended services (different kinds of links).

SFX enables the localization of services and uses the appropriate links.

SFX allows for standardization of services across resources as defined by the librarian.

SFX offers a single point of administration of the various services across different data sources.

SFX provides a wealth of statistics on the usage of distributed resources that has never before been available.

SFX, OpenURL, DOI and CrossRef

The DOI ( www.idf.org), CrossRef (www.CrossRef.org), and OpenURL are complementary frameworks, the components of which can be integrated. Van de Sompel has shown this in a limited experiment (http://www.sfxit.com/crossref/prototype1.html), which is currently being extended into a prototype in which the SFX community and the DOI community collaborate. The prototype integrates the OpenURL and the DOI framework, to enable resolution of DOIs by an SFX server and solving the appropriate copy problem for DOIs. Further information on the testing of this prototype at Los Alamos Research Library can be found at: http://www.sfxit.com/CNI2000.html

More information about Ex Libris and SFX is available from the company's homepage from where a link can be found to SFX and other Ex Libris products. To link directly to SFX use: http://www.sfxit.com This site contains a "Try SFX" section with some live examples of SFX services where you can see what SFX could do for your library services.

Reference

Bush, V. (1945), "As we may think", Atlantic Monthly, available at: http://www.isg.sfu.ca/~duchier/misc/vbush/vbush-all.shtml

Jenny Walker (jwalker@exlibris-usa.com) is Director of Sales and Marketing in the Information Services Division at Ex Libris (USA).