Open Linking and the OpenURL Standard

1. Open Linking and the OpenURL Standard Eric F. Van de Velde, Ph.D. Chair, NISO Committee AX Director of Library Information Technology California Institute of Technology Harry E. Samuels Member, NISO Committee AX Digital Library Projects Coordinator Endeavor Information Systems

2. What Is NISO Committee AX? • A NISO standards committee developing a standard for the OpenURL • Charge of committee • “… Standards Committee AX is charged with developing syntax for creating web-transportable packages of metadata and/or identifiers about an information object...” • Complete statement of charge is at NISO web site at <http://www.niso.org/commitax.html> • Committee web site is at <http://library.caltech.edu/openurl/>

3. What Is Linking? • By linking, we typically mean linking (through the web) • From some source that can provide metadata • To some target that relates to the source

4. Linking Has Been Around • But linking has been controlled by the source • We call this closed linking • There’s nothing wrong with closed linking, but it does have shortcomings

5. Shortcomings of Closed Linking • Typically, sources know little of the user’s context or what the user has access to • They may be static and lack persistence • Most importantly, the source determines the destinations of the links

6. What Is Open Linking? • Open linking introduces a new component into the linking process • The Link Resolver

7. What Does The Link Resolver Do? • A link resolver accepts metadata from a source and presents links based on logic and business rules administered locally • It puts link resolution into the hands of the institution (library) • It knows the user’s context and what the user has access to

8. What Does Open Linking Look Like? Target Link Source Link Resolver Target Metadata Link Link Target

9. What Can the Link Resolver Provide Links To? • Full-text articles - Very powerful tool when source is an article citation • Extended Services • Document delivery request • Inter-library loan request • Initiate a search on an internet search engine based on the received metadata • Initiate a search of the local OPAC (on-line public catalog) based on the received metadata • Any service for which a URL can be constructed

10. What Does Open Linking Look Like? Target Link Resolver OPAC Search Source Target Metadata Full Text Document Delivery Target

11. What Is An OpenURL? • An OpenURL is a transportable metadata package • Typically transported over the web using an HTTP GET or HTTP POST

12. What Does Open Linking Look Like? Target OpenURL standardizes this part of the communication Link Resolver OPAC Search Source Target Metadata Full Text Document Delivery Target

13. What Does Open Linking Look Like? Target Link Resolver OPAC Search Source Target OpenURL Full Text Document Delivery Target

14. What Does an OpenURL Look Like? • http://serv.uni.edu?issn=1234-5678&date=1998&volume=12&issue=2&spage=134 • What Does It Mean? • serv.uni.edu = base URL of link resolver • issn = 1234-5678 • Publication date = 1998 • Volume = 12 • Issue = 2 • Starting Page = 134 • Metadata infers that this is metadata for a journal article

15. OpenURL Also Supports Identifiers? • http://serv.uni.edu?id=doi:123/3456 • What Does This Mean? • serv.uni.edu = base URL of link resolver • Digital Object Identifier = 123/3456

16. In summary... • Linking takes the user from one information resource to a related information resource (via the web) • Open Linking utilizes a link resolver to select and present links to appropriate related information resources independent of the original information resource

17. In summary... • A link resolver requires a package of metadata to determine links to appropriate information resources • OpenURL standardizes the syntax for transmitting a package of metadata to a link resolver

18. In summary... • NISO Committee AX is a NISO standards committee developing a standard for the OpenURL