By Sylvia MacKinnon
Have you ever been frustrated while trying to retrieve the electronic text of an article? A long-standing issue in libraries has been finding a way to ensure easy and accurate access from citations found in indexing and abstracting (I/A) databases to the articles themselves. While full text is becoming more prevalent, it is not always available. Sometimes links exist from I/A databases to the library catalog, where the user can look for a printed copy of the journal among the library's holdings. However, this feature has not been consistently available either. At Penn State Libraries, where databases have grown from 12 when first introduced in 1993 to close to 500 today, the notion of easy movement from the citation to the reference itself is a very important issue.
Since late fall 2004, a growing number of LIAS databases now include a Get it! icon next to many citations. This service is Penn State Libraries' implementation of a link server called SFX, developed by Ex Libris, the library software developer.
Get it! provides links from citations to relevant information elsewhere, such as links to article full text or e-books ... and to holdings in The CAT, the Libraries' online catalog ... to ILLIAD, for Interlibrary loan ... to EndNote libraries for creation of local bibliographies ... and potentially to any other relevant services for which a URL can be constructed. This "context sensitive linking" means that when a user gets to a specific bibliographic record or citation, he or she is directed to a menu that displays a list of services relevant to that particular record or citation. This one-stop shopping opportunity quickly puts the user together with all relevant links for the item requested.
How it Happens: OpenURLs, Sources and Targets
OpenURL, a recently-approved NISO standard, is a protocol for interoperability between an information source and a link server (open URL resolver), in this case SFX. One can think of SFX as a traffic cop of sorts, charged with getting the user from the source (where the search begins, such as an online catalog, electronic journal, or database) to the most relevant targets (where the search ends, at appropriate resources) and without encountering dead links along the way. All this happens via the OpenURL, which enables context-sensitive linking to occur, and lets the library control the link server that provides those relevant links.
OpenURLs are typically transmitted using an HTTP GET or HTTP POST. Embedded within the OpenURL are details needed to get to the specific resource, broken into two parts:
In the "old days of library linking" before the OpenURL and link servers such as SFX ... as recently as five years ago ... linking was called closed linking, and controlled by the source, which determined link destinations. The source was likely unaware of what the user really needed or had access to. The result was that links were determined based on business agreements, with limited linking abilities, and no context sensitivity. Furthermore, up-to-date maintenance of links was virtually impossible, since links often were static and lacked persistence. With SFX, it is library personnel, who understand what users need and what they have permission to access, who determine what appropriate targets should be.
Via Get it!, users can go immediately to the full text, if it is available. If not available, they are transported to other available services that may provide the item, such as the correct bibliographic record in The CAT, or to an interlibrary loan request. In addition to being context sensitive, links are dynamic, delivering different options for different citations, as appropriate. Here's an example from the CSA Aerospace & High Technology Database:
More to Come....
Get it! is just the first Ex Libris service which the University Libraries plans to offer in upcoming months. Another service is a suite of products called MetaLib, which can be customized by the library, as well as by the individual library user. An implementation team within the Libraries is currently working to develop a localized version of MetaLib, which will likely include many features such as those below. Full roll out is expected by fall 2005; we'll talk more about this service in a future ITS Academic Computing Newsletter: