Download Linked Data as An Element to Support Resource Discovery

Linked Data as An Element to
Support Resource Discovery: The
Need for Harmonization of
Metadata Standards
Praveenkumar Vaidya
Librarian, Tolani Maritime Institute, Pune
and
Dr. N. S. Harinarayana, Associate Professor,
DOS LIS, University of Mysore, Mysore
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Preview
• Introduction
• Libraries and Linked Data
• Metadata, Interoperability, crosswalks and
harmonization
• Conclusion
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Introduction
• Information deluge and information overflow.
• Challenge in Information Retrieval.
• Lee’s vision: Semantic Web may be one of the
solutions, where even machines can answer
the queries.
• Bibliographic and subject standards are used
in library world are translated into the
language of Semantic Web and Linked Data.
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Introduction…
• Linked Data is growing body of datasets on the
WWW that are interconnected by means of
the Resource description Framework (RDF).
(W3C, 2004)
• RDF-grammar for a language of data- consistssubject, predicate, object-to form-RDF graph.
• LCSH-2009-Published library standards in RDF.
• W3C-2011-Linked Data Incubator groupaccepted-RDF as tool-integration of Library
Data.
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Libraries and Linked Data
• Basically, to create highly structured
metadata.
• To allow computers to understand the relation
between objects to yield precise web search.
• W3C-working on RDF-allows computer to
understand the meaning of the content rather
just matching text-Result: Web search engine
works like RDBMS-Throws precise search
result.
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Libraries and Linked Data…
• As Freie Universitat Berlin defined- First, to
employ the RDF data model to publish
structured data of the Web. Second, to (use
http URIs) to set explicit RDF links between
data items within different data sources”
• This gives two distinct aspects of Linked Data:
exposing data as RDF and linking RDF entities
together.
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Benefits of Linked Data…
• Sharable, extensible and easily re-usable. With
the concepts like language-agnostic URIs, it
supports multilingual functionality for data
and user services.
• A query can draw related information from
any link that is available on the world wide
network of data, to get useful results from the
web.
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Benefits of Linked Data…
• Links between libraries and non library servicesWikipedia, Geo names, MusicBrainz, the BBC and
The New York Times will connect into larger
universe of the information on the Web which
seamlessly flow to local user.
• If, information Hub linked between Publishers,
Aggregators, Book and Journal vendors, Subject
Authorities, Name Authorities and other Libraries
• Can handle selection, ordering, cataloguing,
authority control, taxonomy development and
search. Can also handle intelligent queries.
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Current Status of Libraries
• Despite movements like DCMI and FRBRLinked Data compatible-Not much has been
integrated with web resource-still in
databases.
• Existing library standards such as MARC
format or information retrieval protocol
Z39.50 are developed for library specific
context -standards should be broadened and
standardized to Linked Data format.
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Current Status of Libraries…
• There is disparity in concepts and terminologies
used between libraries and Semantic Web
communities.
• Essential for both communities to foster mutual
understanding to bring their respective expertise.
• Some hiccups like privacy, trust, rights
management and collaboration with multiple
users exist in full fledge adoption of Linked Data,
much effort is required.
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Towards standardization
• Libraries have four major roles in the Linked
Data
– Exposing collections- use Semantic Web
technologies to make content available
– Webifying thesaurus/mapping /services
– Sharing lessons learned
– Persistence (Miller, 2004)
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Towards standardization…
• W3C Library Linked Data incubator group
(W3C, 2011) insists on Semantic Web
standardization by using available standards
such as Simple Knowledge Organisation
System (SKOS), Web Ontology Language
(OWL) and RDF.
• However, lack of institutional support for
metadata can threaten the long term
persistence.
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Metadata interoperability
• In the networked information environment,
both contents and services are identified as
resources
• Linking these resources is crucial
• Metadata is the key to identify and link these
resources
– Across domains and over time
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Metadata – Fundamental Model
• Definition: (Structured) Data about Data
• Description about a resource from a certain
point of view in accordance with the
requirements in the domain
Metadata
resource
Metadata
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Metadata – Fundamental Model
Different purposes for a single object
I want to find a book
about history of India.
I want to buy a book
about India for my trip.
Bibliographic Information
Book Reviews
Teaching / Learning
Requirements
I want to find a book
appropriate for my class.
Book Classification
I want to properly sort
my bookshelf.
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Metadata – Fundamental Model
Different objects for a same purpose
I want to find a content to
learn history of India.
I want to buy a content
appropriate for my class.
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Why Metadata?
• Users search, access, evaluate a resource, and
pay money for the resource on the network
• Can we do anything without metadata?
Tasks over the Net
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Metadata Interoperability –
Fundamental Issue
• Standards are crucial for interoperability
– International / national standards of metadata schemas,
e.g. MARC, MODS, METS, Dublin Core, ISAD(G), PREMIS,
OAIS, etc.
• Metadata is used on the Web / Internet
 Open Community, Use/Reuse resource across
communities
– Conventional standards are designed by and for a specific
community (-ies)
• Metadata Interoperability across Communities and
over Time
– Need to collect, preserve and provide access to metadata
schemas
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Metadata Interoperability…
• Interoperability is a key issue for metadata
– Interoperability across communities
– Interoperability over time --- Preservation
• A fundamental barrier is the semantic gap
between communities
– Same word but different concepts
– Different words for a same concept
– Linked Open Data – Sharing concepts expressed as
data, i.e., terms, phrases, etc.
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Metadata Interoperability…
• Promote sharing and reuse of metadata
vocabularies
– Metadata vocabulary – a controlled set of terms used
to express metadata – is semantic basis of metadata
– “Sharing Metadata Vocabulary” = “Sharing Concepts”
• Application Profile concept of Dublin Core
– Mixing and matching metadata vocabularies
– Clear separation of metadata vocabularies and
structural constraints in a metadata schema
– Share semantics by sharing metadata vocabularies
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Metadata Interoperability…
• Resource Description Framework is a crucial
standard to share metadata on the Web.
• Application Profile is separation of
– Metadata terms (metadata vocabulary), and
– Structure definition (or structural constraints)
• Concrete syntax and other related information
should be included in a complete metadata schema
definition.
– Singapore Framework gives a framework to define
application profiles
http://dublincore.org/documents/singapore-framework/
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Is Linked Data the answer?
•
•
•
•
•
YES, but we have more to do than simply linking.
No panacea for metadata interoperability.
Use standards commonly used on the web.
Do not reinvent the metadata schemas.
Use or reuse the existing one
– By sharing Metadata vocabularies and Application
Profiles
• Necessity of all available standards to come
together and integrate with different domains.
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Acknowledgement
• I thank Prof. Shigeo Sugimoto, University of
Tsukuba, Japan allowing me to use few of his
slides for this presentation.
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References: References:
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Berners-Lee, T. (2006), “Linked Data–design issues”, available
at:http://www.w3.org/DesignIssues/LinkedData.html
DCMI Bibliographic Metadata Task Group (2011), available at
http://wiki.dublincore.org/index.php/Bibliographic_Metadata_Task_Group
Library of Congress (2011), “A bibliographic framework for the digital age”, available at:
http://www.loc.gov/marc/transition/news/framework-103111.html
Nilsson,M and Naeve, A. (2010) Metadata harmonization:a roadmap for standardization
available at Nilsson, M. (2010), “From interoperability to harmonization in metadata
standardization:Designing an evolvable framework for metadata harmonization,” Kungliga
TekniskaHögskolan, Stockholm, available
at:http://kmr.nada.kth.se/papers/SemanticWeb/FromInteropToHarm-MikaelsThesis.pdf
W3C (2010) Semantic Web, available at http://www.w3.org/standards/semanticweb/
W3C (2011) Library Linked Data Incubator Group Final Report, W3C Incubator Group Report
25 October 2011, available at: http://www.w3.org/2005/Incubator/lld/XGR-lld-20111025/
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Thank you very much
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