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The FAQs on SFX

What is SFX?
SFX is an exciting new research tool that is now available to the Harvard community. It is a resource-linking technology that allows users of research databases to link directly from an article citation or abstract in an external database to a variety of related resources determined by the local library or institution.

SFX can provide access to the full text of an article (if available) or to local holdings in the online catalog. SFX permits context-sensitive linking between web-based resources in which the actual links are customized to reflect licensed digital resources available to users affiliated with the local institution.

How did SFX get its name?
The acronym "SFX" is used in the theatre and film industry to indicate "special effects." The acronym was adopted for this resource-linking technology because it significantly enlivens a researcher's interaction with scholarly information.

How does it work?
A library using SFX creates a database on its local server that contains detailed information about its own institutionally licensed electronic resources—and about other resources available to users.

A research database (e.g., ProQuest or INSPEC) that is SFX-enabled displays an SFX button—often branded for the user's local institution—next to citations and/or abstracts. When a user clicks on the SFX button for a particular citation, the database builds a special, standardized URL (called an OpenURL) that passes metadata and identifier information to the local SFX server. Using the information from this OpenURL, the local server queries the database and determines the links that can be offered for a specific citation. SFX then dynamically constructs a menu of links that it presents to the user. By clicking on one of these links, the user is taken directly to the linked resource.

What are the advantages to users?
SFX streamlines research by providing direct links from the citation to the full text, holdings, or other relevant resources. SFX eliminates the extra step of accessing and re-executing searches in other databases. It alleviates the frustration for users of being linked to resources to which they do not have access.

SFX simplifies electronic research by ensuring easy access to materials from heterogeneous sources. It also recreates some of the serendipity of browsing the stacks to discover related resources.

What are the advantages to libraries?
SFX puts the library or overall institution in control of the linking environment, determining the resources to be linked and the manner of their interlinking. It allows for simplified management of links between numerous and diverse resources, and allows customization of the linking icon and menu of links with institutional branding. SFX provides data on a large number of analyzed resources in a database, updated on a continual basis, and also provides usage statistics for resources in the database.

What problems does SFX solve?
Previous attempts at linking from the citation level have had the following disadvantages:

  • Many of the links are static and embedded in documents at the time of their creation. This approach is not scalable and the resulting links often become less reliable over time.
  • Some linking is dynamic, but places the links under the control of the vendor, not the library or local institution.
  • The links are not context-sensitive and don't take into account the subscriptions and access rights of the local institution.
  • The scope of the links is normally limited to full text and not to other potential resources.

SFX eliminates the need to search different systems to retrieve relevant text and information.

What will the Harvard user see?
The user will see a Harvard SFX button (see right) in SFX-enabled databases, either at the citation or abstract level. The appearance and location of the button is controlled by the database vendor (the source), so it may vary from source to source. The button will normally appear as it does on this page, although there may be variations due to vendor requirements.

After pressing the button, the user will be presented with a menu of links (see illustration on the right). Only links that are relevant for the current citation will be displayed.

Which research databases will we start with at Harvard?
Harvard will initially implement SFX in the following "source" databases, which can be accessed at the "Harvard Libraries" web site found at

  • Cambridge Scientific Abstracts
  • Elsevier Science Direct
  • Gale
  • IOP-Axiom (INSPEC)
  • ISI Web of Science
  • OCLC First Search
  • Ovid
  • ProQuest

Additional databases will be SFX-enabled over the next few months.

How many target resources do we have in the Harvard SFX database?
There are approximately 8,000 full-text electronic resources in the Harvard SFX database, including licensed or free E-journals. For a list of current Harvard SFX "target" aggregations and publisher collections, visit

What is the SFX Citation Linker?
The SFX Citation Linker is a web facility that allows the user to enter information directly for a specific article or journal citation so that they may generate an SFX menu of links for that citation.

The more complete and accurate the information entered, the more accurate and granular the resulting links. Citation Linker will be available from the E-resources search page on the Harvard Libraries web site ( and from the E-journals page.

Is there a list of resources that can be generated from the SFX knowledge database?
Yes, it is possible to generate a list of individual resources from the SFX database, and we are looking at this as a possible solution (among others) for access to individual electronic journals in aggregations.

Does SFX interact with the DOI (Digital Object Identifier)?
The Digital Object Identifier (DOI) is a system for identifying and exchanging intellectual property in the digital environment, and CrossRef is the DOI agency for scholarly journals.

There are two major scenarios in which SFX is integrated with DOI and linking solutions.

  • It is possible to click on a DOI link in an article reference and invoke SFX. The DOI proxy server redirects the user to our SFX server which, using the DOI as an identifier, queries the CrossRef database for additional metadata (author name, volume, issue, page, etc). The SFX server can then use this data to create the menu of links.
  • Some vendors send the DOI instead of the ISSN in the OpenURL created for a citation. In this case, the SFX server again queries the CrossRef database for identification and additional metadata, and then uses the information to create its links.

What is the OpenURL standard and where can I find more information about it?
The OpenURL standard allows for descriptive metadata elements and identifiers to be transported from a research database to the SFX server. Typically, information providers offer the OpenURL linking capability alongside their default, resource-specific links.

For more information about the OpenURL standard, refer to: and

What happens if the SFX link is not working?
If SFX is unable to construct a valid search (e.g., lack of ISSN/ISBN/title), no links will be retrieved. In this case, a message will instruct the user to check the catalog or to ask a librarian. Staff, as well as users, should use the comment facility on the SFX links menu to report SFX problems to OIS.

What's in the future for SFX?
Information providers are beginning to enable SFX buttons for bibliographic references in articles. SFX can also be enabled within the HOLLIS catalog for links to related items. There are potentially many additional links, or "targets," that can be enabled for a citation, including encyclopedias, subject gateways, union lists, patent databases, directories, etc. Library staff at Harvard and elsewhere will have an increasing ability to develop creative linking scenarios for their users, while at the same time needing to be careful about raising expectations and creating frustrating dead-end links.

Who owns SFX?
SFX is owned by Ex Libris, developer of the Aleph software on which the new HOLLIS is based.

Who is responsible for SFX at Harvard?
SFX is implemented and maintained by the Harvard University Library's Office for Information Systems. A University-wide group of librarians meets regularly to guide the SFX implementation at Harvard.

Who else is using SFX?
There is a growing list of libraries using SFX, including Yale, Brown, Boston College, University of Chicago, Caltech, the California Digital Library, and other academic institutions around the world. SFX is not limited to users of the Ex Libris Aleph software.

Is there further information about SFX?

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Last modified on Thursday, January 16, 2003.