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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. Preview. Introduction
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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
Preview • Introduction • Libraries and Linked Data • Metadata, Interoperability, crosswalks and harmonization • Conclusion
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.
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- consists-subject, predicate, object-to form-RDF graph. • LCSH-2009-Published library standards in RDF. • W3C-2011-Linked Data Incubator group-accepted-RDF as tool-integration of Library Data.
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.
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.
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.
Benefits of Linked Data… • Links between libraries and non library services- Wikipedia, 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.
Current Status of Libraries • Despite movements like DCMI and FRBR-Linked 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.
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.
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)
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.
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
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 Metadata resource
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. Book Reviews Bibliographic Information Teaching / Learning Requirements Book Classification I want to properly sort my bookshelf. I want to find a book appropriate for my class.
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.
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
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
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.
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
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 profileshttp://dublincore.org/documents/singapore-framework/
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.
Acknowledgement • I thank Prof. Shigeo Sugimoto, University of Tsukuba, Japan allowing me to use few of his slides for this presentation.
References: References: • 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,” KungligaTekniskaHögskolan, 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/