Post on 31-Dec-2015
Text linking in the humanities:citing canonical works using OpenURL
CNI Spring 2009 Task Force Meeting
Eric Rebillard
Departments of
Classics and History
David Ruddy
University Library
Planning grant overview
• Mellon Foundation funding• Three components
– Canonical citation– OpenURL quality metrics and evaluation– L’Annee interface enhancements
Linking solutions
• Bilateral, direct vendor links– Costly to implement and maintain– Unstable– Does not easily allow one-to-many relationships– Does not address ‘appropriate copy’ problem
• A method with more indirection, such as OpenURL
OpenURL
Classical text resource
(e.g., JSTOR, L’Annee)
Source text in translation
Source text in translation
Library catalog
Library catalog
Inter-library loan
Inter-library loan
Source text in original language
Source text in original language
Others?Others?
HTML page with link options
HTML page with link options
User’s link resolver
OpenURL
• OpenURL: a package of metadata about a resource, encoded within a URL and sent to a user’s link resolver
• OpenURL Framework (2004) generalized and formalized OpenURL 0.1 (2000) architecture so that services can be extended and new applications can evolve
• Focus on allowing “context-sensitive” services related to a specific resource
Advantages of using OpenURL
• System/vendor independent• Uniform linking syntax• Minimizes cost of creating and maintaining
links• Easily allows one-to-many linking• Allows appropriate copy
OpenURL in practice
• Define a metadata format that can reliably reference canonical citations
• Devise a feasible implementation plan
Metadata format: Identifying the work
• Canonical citations are at the level of the FRBR work
• Very little metadata (a title, possibly an author name)
• An undefined work ID included in metadata format– Community defined?– ISTC?
Metadata format: Author names
• Existing OpenURL metadata formats expect modern, western names (aufirst, aulast)
• How to capture ancient author names?– Allowing multiple ways to encode author forms,
which may depend on era of author
aufirst auform1aulast auform2
Metadata format: Citation components
• Two possible approaches:– Try to define every component
• Book, section, canto, stanza, act, scene, etc.
– A more abstract approach, recognizing the typical hierarchical structure of works
• level_1, level_2, level_3
• Second approach more generally applicable across heterogeneous material
Implementation challenge
• Normally, resolution to resource is left to local link resolver
• And yet:– Detailed and specialized knowledge – Uncertain commercial incentive for link resolver
vendors
• Proposed solution: domain-specific, community-supported knowledge bases
OpenURL
Classical text resource
(e.g., JSTOR, L’Annee)
Service X Text in original language, Edition B
Service X Text in original language, Edition B
Service Y Text in original language
Service Y Text in original language
Service Z Text in translation
Service Z Text in translation
Service X Text in original language, Edition A
Service X Text in original language, Edition A
Others?Others?
HTML page with link options
HTML page with link options
Classical Works KnowledgeBase
(CWKB)
Problems with this approach
• Doesn’t solve appropriate copy problem• Doesn’t allow for institutional branding,
presentation, page layout• Doesn’t allow for local options (library catalog
search, etc.)
OpenURL
Classical text resource
(e.g., JSTOR, L’Annee)
Inter-library loan
Inter-library loan
Library catalog
Library catalog
Others?Others?
HTML page with link options
HTML page with link options
Classical Works KnowledgeBase
(CWKB)1
User’s link resolver
OpenURL2
Service Y Text in original language
Service Y Text in original language
Service Z Text in translation
Service Z Text in translation
Advantages of intermediate resolver / knowledge base
• Domain specific knowledge base can augment and/or normalize metadata values
• Can provide specialized linking information• Can allow direct access to targeted resources
for users without a local link resolver • Could provide other potential services to
community
OpenURL
Classical text resource
(e.g., JSTOR, L’Annee)
Inter-library loan
Inter-library loan
Library catalog
Library catalog
Service XText in original language
Service XText in original language
HTML page with link options
HTML page with link options
Classical Works KnowledgeBase
(CWKB)1
User’s link resolver
OpenURL2
Service Y Text in original language
Service Y Text in original language
Service Z Text in translation
Service Z Text in translation
CWKBURLredirectservice
CWKB: Classical Works Knowledge Base
• A relational database that stores metadata about classical works
• A link resolver software that does the lookup in the relational database
CWKB: the database
CWKB: Author’s name
• The Latin form is the international authority form for Latin and ancient Greek authors.
• For lookup purpose, CWKB will store the established form of the author in several modern languages and the abbreviations used by the main reference tools.
• Draft ISO standard 27729: International Standard Name Identifier (ISNI)
CWKB: Work’s title
• The Latin form is the international authority form for Latin and ancient Greek titles.
• For lookup purpose, CWKB will store the established form of the title in several modern languages and the abbreviations used by the main reference tools.
CWKB: work identifiers
• They may come from a range of well-established registries such as:
• They may come from a range of well-established registries such as:– The Canon of the TLG– The Clavis Patrum Latinorum– The Clavis Patrum Graecorum– The CHS Canon of Greek Literature– The Stoa Canon of Latin Literature
• CWKB will maintain a concordance between them.• One development to follow: the ISTC standard (ISO 21047).
CWKB: the link resolver
OpenURL
Classical text resource
(e.g., JSTOR, L’Annee)
HTML page with link options
HTML page with link options
Classical Works KnowledgeBase
(CWKB)1
User’s link resolver
OpenURL2
OpenURL 1
Baseurl: cwkb.org/in/r.php? OpenURL version: ctx_ver = Z39.88-2004Metadata format: rft_val_fmt = info:ofi/fmt:kev:mtx:canonical_cit Citation: rft_auform1 = Aeschylus
rft_titleform1 = Suppliants rft_slevel1 = 40 rft_elevel1 = 57
User’s resolver: res_id =
http://resolver.library.cornell.edu/net/openurl/? Source’s id: rfr_id = info:sid/aph
OpenURL 1 (cont.)
http://cwkb.org/in/r.php?ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:canonical_cit&rft.auform1=Aeschylus&rft.titleform1=Suppliants&rft.slevel1=40&rft.elevel1=57&res_id=http://resolver.library.cornell.edu/net/openurl/?&rfr_id=info:sid/aph
OpenURL 2
Step 1
The link resolver software looks up in the database for a match on the author’s name and the work’s title.
Step 2
The link resolver software adds data to the incoming OpenURL 1:
• authority forms of the author and the work (used for the lookup in the local library catalog);
• data on the services providing full text for the citation sent as an OpenURL ServiceType identifier.
The ServiceType identifiers contain the name of the service and the full text url.
Ex. &svc_id=info:sid/cwkb.org:perseus_eng:url:http://www.perseus.tufts.edu/hopper/text.jsp?doc=Perseus:text:1999.01.0016:line=40.
If the service does not accept GET requests, the link goes to CWKB and is resolved.
OpenURL 2 (cont.)
http://resolver.library.cornell.edu/net/openurl/?&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:canonical_cit&rfr_id=info:sid/cwkb.org&rft.auform1=Aeschylus&rft.titleform1=Suppliants&rft.titleform2=Supplices&rft.auform2=Aeschylus&rft.slevel1=40&svc_id=info:sid/cwkb.org:tlg_demo:url:http://cwkb.org/in/tlgpost.php?package_id=tlg_demo%26local_package_id=0085001%26scheme=z%26hidden_z=40&svc_id=info:sid/cwkb.org:tlg:url:http://cwkb.org/in/tlgpost.php?package_id=tlg%26local_package_id=0085014%26scheme=z%26hidden_z=40&svc_id=info:sid/cwkb.org:perseus_eng:url:http://www.perseus.tufts.edu/hopper/text.jsp?doc=Perseus:text:1999.01.0016:line=40&svc_id=info:sid/cwkb.org:perseus_grk:url:http://www.perseus.tufts.edu/hopper/text.jsp?doc=Perseus:text:1999.01.0015:line=40
Local Link Resolver
CWKB will provide a set of instructions for:• Creating a resource profile for each canonical citation
package the library licenses or supports;• Establishing rules for displaying the full text links;• Creating rules for mapping canonical citation
metadata to non-full text services, such as the library catalog searches.
Local Link Resolver
• Recognize the format of the incoming OpenURL. Each one will contain this string: rft_val_fmt=info:ofi/fmt:kev:mtx:canonical_cit
• Parse each incoming canonical citation in its key value components: – Pull out each svc_id into two parts (name of the
service; full text url);– Use auform2 and title2 for the display of the citation
requested and for the search in the local catalog.
Local Link Resolver
The OpenURL 2 is thus interpreted by the local link resolver to produce a page such as this:
Wider application
• Potential value to any discipline that cites works independent of specific editions or translations
• Potential model for chaining link resolvers / knowledge bases together to provide enhanced services to users
• Potential for providing other information services to community