[June 30, 2000] "The Dublin Core Metadata Initiative is a cross-disciplinary international effort to develop mechanisms for the discovery-oriented description of diverse resources in an electronic environment. The Dublin Core Element Set comprises fifteen elements which together capture a representation of essential aspects related to the description of resources. The majority of work on the Dublin Core has addressed the definition of semantics rather than syntax or structure, allowing rapid conceptual development free of the constraints imposed by specific implementation environments. Whilst beneficial in many ways, this has led to a certain lack of clarity at times, especially in relation to development of 'qualification' mechanisms which enrich descriptions in the Dublin Core. It has also made interoperable implementation difficult, as individual implementors have typically developed their own internal mechanisms for actually encoding Dublin Core; mechanisms which are not always compatible with those of their potential collaborators elsewhere. . . The Dublin Core Data Model working group was set up to look at means by which the richness of the Dublin Core model might be expressed outwith the limitations of HTML. This document represents a technical report on two specific outcomes from this process; a means by which the model may be considered, extended, tested and manipulated within the Resource Description Framework (RDF); and suggested mechanisms by which both simple and complex Dublin Core might be expressed using the eXtensible Markup Language (XML), the formal syntax of RDF. Although RDF is the 'language' used to express the data model, users are not limited to using only RDF in their own applications. Similarly, although examples throughout this document are expressed in XML, this does not mean the Dublin Core may only be encoded in this way. The following sections introduce the building blocks upon which this document relies, such as XML and RDF. . . Originally developed from very separate ideas, the current convergence of the concepts behind Dublin Core with the syntactic and structural facilities offered by XML and RDF offers a powerful weapon in the arsenal of those manipulating and using the wealth of information with which we are surrounded. Dublin Core offers a means by which diverse resources might be described for discovery in an interdisciplinary context, and XML/RDF provides the structure for unambiguous expression of this Dublin Core information, as well as the straightforward addition of more detailed descriptions from the communities concerned. . ." [from the DC-RDF document]
The Dublin Core Metadata Element Set (the Dublin Core) "is a 15 element metadata set that is primarily intended to aid resource discovery on the Web. The elements in the Dublin Core are TITLE, SUBJECT, DESCRIPTION, CREATOR, PUBLISHER, CONTRIBUTOR, DATE, TYPE, FORMAT, IDENTIFIER, SOURCE, LANGUAGE, RELATION, COVERAGE and RIGHTS. The metadata elements fall into three groups which roughly indicate the class or scope of information stored in them: (1) elements related mainly to the Content of the resource [Title, Subject, Description, Type, Source, Relation, Coverage], (2) elements related mainly to the resource when viewed as Intellectual Property [Creator, Publisher, Contributor, Rights] and (3) elements related mainly to the Instantiation of the resource [Date, Format, Identifier, Language]."
"The Dublin Core Metadata Initiative (DCMI) is a consensus building organization that has relationships in many standards activities. A number of people in the DCMI are active in the W3C (DC is the prototype application that drove the development of the Resource Description Framework, or RDF in the W3C). Our own standardization activities take place in the IETF (RFC 2413 is reference description of the initial version of the Dublin Core), and there are currently formal DC standardization activities underway in CEN (the European information industry standardization forum) and in NISO (the North American information standardization organization)."
References:
[March 19, 2005] "DCMI and ODRL: A Discussion Paper." By Andy Powell (Distributed Systems, UKOLN, University of Bath, Bath, UK; WWW). Contribution posted to the mailing list of the ODRL/DCMI Profile Working Group. "This discussion paper considers some of the issues related to bringing together the use of DC metadata and ODRL. It takes a DCMI-centric view, since, of the two standards, DC is the one with which the author has most familiarity. It starts with a summary of the capabilities of DC metadata and then presents some potential use cases that describe how the combined use of DC and ODRL may benefit the end-user. Finally, it outlines some of the issues that the ODRL-DCMI working group will have to address... DCMI provides a growing set of metadata terms (elements, element refinements, encoding schemes and controlled vocabularies) and three encoding syntaxes (XHTML, XML and RDF) that allow those terms to be used in a wide variety of resource discovery applications. These are underpinned by the DCMI Abstract Model, which provides a description of the key entities that make up DC metadata records. A number of DCMIs terms are valid in the context of encoding rights-related information: Contributor, Creator, Publisher, Rights Management, Access Rights, Date Copyrighted, License, Provenance, Rights Holder... The encoding guidelines currently endorsed by the DCMI currently have different capabilities with respect to the DCMI Abstract Model, i.e., not all features of the model can be encoded in all the syntaxes. The RDF encoding can encode almost all aspects of the model and is therefore the richest. The XML and XHTML guidelines do not support all parts of the model. It is therefore the case that, currently, descriptions that can be encoded in one syntax may not be able to be encoded in the other syntaxes... With the exception of those cases where both DC metadata and ODRL are encoded using RDF/XML, it seems more sensible consider how to link together, rather than merge, DC metadata description and ODRL documents..." For context and other references, see ODRL Profiles. [cache]
[February 2005] ODRL DCMI Profile. In February 2005 the Dublin Core Metadata Initiative (DCMI) and Open Digital Rights Initiative (ODRL) announced the formation of a joint ODRL/DCMI Profile Working Group to develop a profile of ODRL/DCMI metadata usage. This profile "will show how to make combined use of the rights-related DCMI metadata terms and the ODRL rights expression language. This will enable richer rights management information to be captured along with DCMI descriptive metadata and support wider interoperability with digital rights management and open content licensing systems. The joint Working Group Chairs are Andy Powell (UKOLN, University of Bath) and Renato Iannella (ODRL Initiative)." ODRL Profiles were first announced at the ODRL International Workshop in April in Vienna (2004) as a formal means of showing how to use ODRL in specific technical environments. Profile Working Groups have now been formed to create ODRL Profiles for Geospatial Data, for Dublin Core Metadata Initiative (DCMI) encoding, and for Creative Commons licenses. See also the ODRL DCMI Profile Working Group mailing list and archives.
[April 15, 2003] "State of the Dublin Core Metadata Initiative, April 2003." By Makx Dekkers (Managing Director, DCMI) and Stuart Weibel (Consulting Research Scientist, OCLC Office of Research). "The Dublin Core Metadata Initiative continues to grow in participation and recognition as the predominant resource discovery metadata standard on the Internet. With its approval as ISO 15836, DC is firmly established as a foundation block of modular, interoperable metadata for distributed resources. This report summarizes developments in DCMI over the past year, including the annual conference, progress of working groups, new developments in encoding methods, and advances in documentation and dissemination. New developments in broadening the community to commercial users of metadata are discussed, and plans for an international network of national affiliates are described... Version 1.1 of the Dublin Core Metadata Element Set was balloted in the International Standards Organization (ISO) as DIS 15836. In January 2003, the ballot finished with 18 'yes' votes and without any 'no' votes. Publication as ISO 15836 will be forthcoming in the near future. Publication of this standard culminates a series of standardization work by the Internet Engineering Task Force, CEN (the European consortium of standards bodies), the National Information Standards Organization (NISO) in the US, and now in the international domain. Ratification of the Dublin Core Metadata Element Set within ISO illustrates that it is indeed a standard for all nations, serving as a foundation for global metadata interoperability... The specification of the expression of simple Dublin Core metadata in RDF/XML became a DCMI Recommendation in October 2002. The specification for the RDF/XML expression of qualified Dublin Core metadata and the finalization of the necessary RDF schemas are being progressed further in co-operation with representatives of W3C, taking into account recent changes in the W3C RDF specifications. The Proposed Recommendation for the expression of Dublin Core metadata in XML was made available for Public Comment during the month of March 2003. A new XML schema for simple Dublin Core metadata was published in December 2002..."
[April 15, 2003] "Guidelines for implementing Dublin Core in XML." Dublin Core Metadata Initiative Recommendation. 2003-04-02. Edited by Andy Powell and Pete Johnston (UKOLN, University of Bath). "This document provides guidelines for people implementing Dublin Core metadata applications using XML. It considers both simple (unqualified) DC and qualified DC applications. In each case, the underlying metadata model is described (in a syntax neutral way), followed by some specific guidelines for XML implementations. Some guidance on the use of non-DC metadata within DC metadata applications is also provided... At the same time, a new set of XML schemas is published. These support the encoding of Qualified Dublin Core metadata records, including the use of element refinements and encoding schemes, and follow the conventions described in Guidelines for expressing Dublin Core in XML..."
[January 24, 2003] An updated (W3C) XML Schema defining terms for Simple Dublin Core has been posted on the DCMI website, referenced from DCMI term declarations represented in XML schema language. This XML schema in the earlier 2002-03-12 version defined the fifteen (15) elements from the http://purl.org/dc/elements/1.1/ namespace, with no use of encoding schemes or element refinements; the default content type for all elements was xs:string with an xml:lang attribute available. Viz., title, creator, subject, description, publisher, contributor, date, type, format, identifier, source, language, relation, coverage, [and] rights. The update version has been "amended to remove namespace declaration for http://www.w3.org/XML/1998/namespace namespace, and to reference the optional lang attribute via built-in xml: namespace prefix. The xs:appinfo has also been removed." XML schemas for Qualified Dublin Core are currently under development and are expected to become available in early 2003. See also the DCMI term declarations represented in RDF schema language, in preparation. See also the list of current DCMI elements and element refinements. Cache: version 2002-12-12, version 2002-03-12.
[December 17, 2002] "Expressing Simple Dublin Core in RDF/XML." Dublin Core Metadata Initiative Recommendation, Approved 2002-10-25. Edited by Dave Beckett (Institute for Learning and Research Technology - ILRT, University of Bristol), Eric Miller (W3C), and Dan Brickley (W3C/ILRT). Latest version URL: http://dublincore.org/documents/dcmes-xml/. Draft issued 2002-07-31. In October 2002 the DCMI Directorate announced that the document Expressing Simple Dublin Core in RDF/XML had been approved as a DCMI Recommendation. "This is the first in a series of recommendations for encoding Dublin Core metadata using mainstream Web technologies. Other guidelines that are in process at this moment are guidelines for the expression of Qualified Dublin Core in RDF/XML, guidelines for implementing Dublin Core in XML and an updated version of the guidelines for expressing qualified Dublin Core in HTML/XHTML meta elements." ['This document explains how to encode the DCMES in RDF/XML, provides a DTD to validate the documents and describes a method to link them from web pages.'] From the Introduction: "The Dublin Core Metadata Element Set V1.1 (DCMES) can be represented in many syntax formats. This document gives an encoding for the DCMES in XML using simple RDF, provides a DTD and W3C XML Schemas to validate the documents and describes a method to link them from web pages. This document describes an encoding for the DCMES in XML subject to these restrictions: (1) The Dublin Core elements described in the DCMES V1.1 reference can be used; (2) No other elements can be used; (3) No element qualifiers can be used; (4) The resulting RDF/XML cannot be embedded in web pages. The primary goal for this document is to provide a simple encoding, where there are no extra elements, qualifiers, optional or varying parts allowed. This allows the resulting data to be validated against a DTD and guaranteed usable by XML parsers. A secondary goal was to make the encoding also be valid RDF which allows the document to be manipulated using the RDF model. We have tried to limit the RDF constructs to the minimum, and the result is a standard header and footer for every document..."
[December 16, 2002] "A Quantitative Analysis of Dublin Core Metadata Element Set (DCMES) Usage in Data Providers Registered with the Open Archives Initiative (OAI)." By Jewel Ward (Graduate Student, The School of Information and Library Science, Univ of North Carolina at Chapel Hill; WWW). November, 2002. 68 pages. A Master's paper for the MS degree in I.S. Abstract: "This research describes an empirical study of how the Dublin Core Metadata Element Set (DCMES) is used by 100 Data Providers (DPs) registered with the Open Archives Initiative (OAI). The research was conducted to determine whether or not the DCMES is used to its full capabilities. Eighty-two of 100 DPs have metadata records available for analysis. DCMES usage varies by type of DP. The average number of Dublin Core elements per record is eight, with an average of 91,785 Dublin Core elements used per DP. Five of the 15 elements of the DCMES are used 71% of the time. The results show the DCMES is not used to its fullest extent within DPs registered with OAI..."
[August 09, 2002] "Recommendations for XML Schema for Qualified Dublin Core." Proposal to the Dublin Core Architecture Working Group. From the Ad-hoc Committee: Timothy Cole (UIUC), Thomas Habing (UIUC), Diane Hillmann (Cornell), Jane Hunter (DSTC), Pete Johnston (UKOLN), Carl Lagoze (Cornell), and Andy Powell (UKOLN). 2002-07-14. "This document is a follow-on to three efforts: (1) Publication of the Dublin Core Qualifiers recommendation document. (2) Publication of the DCMI proposed recommendation Guidelines for Implementing Dublin Core in XML [We propose an amendment to Recommendation 7 of this document to indicate that references to encoding schemes should be represented using an xsi:type attribute of the XML element for that property, in line with the conventions used in the schemas proposed here]; (3) Joint work between the Open Archives Initiative and the DCMI to define an XML schema for unqualified Dublin Core; this work was motivated by the requirements of the base metadata format for the OAI Protocol for Metadata Harvesting, but is useful for other applications that exchange unqualified Dublin Core records. The schema presented in this document conform to the W3C XML Schema (1.0) recommendations. They are suggested rather than prescribed and may, in fact, co-exist with other schema for exchanging Dublin Core metadata. XML schema are interoperability vehicles; the greater number of applications that agree on a single schema the greater the ability to easily share Dublin Core metadata. Therefore, while the committee that formulated this proposal hopes that the proposed schema will be useful to a breadth of applications, we recognize that different functionality, provided by different schema, may be required by some... While the schema presented here are indeed suggested, the functionality they support is congruent with the qualification model in the Dublin Core Qualifiers document. Therefore, applications that employ other schema that express additional functionality should recognize that doing so compromises interoperability with applications that use this schema. See also the note of July 26, 2002 in "DCMI release new XML Schema proposal for Dublin Core metadata specification": "The Dublin Core Metadata Initiative (DCMI) have released a proposed new XML Schema for Qualified Dublin Core metadata. According to Carl Lagoze, one of the group producing the proposal, the "continued absence of such solid guidelines on how to deploy qualified Dublin Core has interfered with the interoperability goals of DCMI." An XML Schema binding of unqualified Dublin Core metadata had been released by DCMI previously, but this is the first XMLS Schema for qualified Dublin Core..."
[February 28, 2002] "Dublin Core Metadata Initiative Progress Report and Workplan for 2002." By Makx Dekkers (Managing Director, Dublin Core Metadata Initiative) and Stuart L. Weibel (Executive Director, Dublin Core Metadata Initiative). "The Dublin Core Metadata Initiative (DCMI) progressed on many fronts in 2001, including launching important organizational changes, achievement of major objectives identified in the previous year, completion of ANSI standardization, and increased community participation and uptake of the standard. The annual workshop, held in Asia for the first time this past October, was broadened in scope to include a tutorial track and conference. This report summarizes the accomplishments and changes that have taken place in the Initiative during the past year and outlines the workplan for the coming year... DCMI remains committed to its mission to serve the user community, to further develop its role in the wider context of the semantic Web, and to create a stable platform for future developments and outreach to the commercial sector (especially product development and knowledge technologies). DC and OAI: The initial version of the OAI protocol calls for the use of unqualified Dublin Core as the required default metadata set. However, implementation of this recommendation is not without difficulty, and may result in awkward representation of some types of resources. In addition, the current protocol associates an OAI-specific XML schema with the DC namespace rather than pointing to the DCMI-maintained site. Recent concerns about these issues in both communities have resulted in closer liaison between their technical groups, and this is expected to result in collaborative efforts to resolve these issues in the coming year... Expression of simple and qualified Dublin Core in RDF/XML: Two documents were finalized in 2001 and are expected to become DCMI Recommendations in early 2002. The first of these documents explains how to express unqualified Dublin Core metadata in RDF with XML syntax, and contains many encoding examples. The second document addresses the more complex case of encoding qualified Dublin Core in RDF... Development of Library and Government Application Profiles: Two communities have been active in defining how to use Dublin Core metadata in their domain: the library community and the government community. These groups are in the process of defining Application Profiles and identifying additional implementation rules and controlled vocabularies (thesauri, ontologies) that will allow implementations in these domains to achieve a high level of interoperability... Expression of Dublin Core metadata in XML: Following the recommendations on how to express Dublin Core metadata in RDF/XML, a need has been identified for a similar recommendation how to express DC metadata in XML without the use of RDF. A draft of such a recommendation has been prepared in 2001 and is expected to go through finalization and review in 2002 as one of the activities in the Architecture working group... In 2001, we have seen important achievements, both in the technical area as well as in the organizational restructuring of the Initiative. The 2002 workplan is well underway and moving towards DC-2002, to be held in Florence, Italy in October of this year. The commitment of the many people who invest their time, energy and intellectual resources to develop the Dublin Core gives ample reason for optimism that DCMI will continue to lead the development of cross disciplinary resource discovery standards for the Web..."
Dublin Core Qualifiers. 2000-07-11 This document presents the results of a process to develop exemplary qualifiers for the Dublin Core Metadata Element Set (DCMES). The qualifiers listed here were identified in element-specific working groups of the Dublin Core Metadata Initiative (DCMI) and judged by the DCMI Usage Committee to be in conformance with principles of good practice for the qualification of Dublin Core metadata elements... At the time of the ratification of this document, the DCMI recognizes two broad classes of qualifiers: (1) Element Refinement. These qualifiers make the meaning of an element narrower or more specific.... (2) Encoding Scheme. These qualifiers identify schemes that aid in the interpretation of an element value; these schemes include controlled vocabularies and formal notations or parsing rules.."
"Guidance on expressing the Dublin Core within the Resource Description Framework (RDF)." Edited by Eric Miller, Paul Miller and Dan Brickley.
[June 21, 2001] "Augmented Metadata in XHTML." Sun Microsystems Working Draft 21-June-2001. Edited by Murray Altheim (Sun Microsystems) and Sean B. Palmer. Draft version for feedback ('work in progress). Abstract: "This specification describes several minor syntax modifications to XHTML (the XML transformation of HTML) which provide much of the essential functionality required to augment Web pages with metadata as found in published descriptions of the Semantic Web. This augmentation allows Dublin Core metadata, a highly popular standard developed by the library community to be incorporated in Web pages in a way that is compatible with today's Web browsers, and describes a generalized mechanism by which other popular schemas can be used in similar fashion. The metadata can be associated with any XHTML or XML document or document fragment (actually, any addressable resource), internal or external to the document." Detail: "This specification describes three minor modifications to XHTML 1.1 which provide much of the essential functionality required to augment Web pages with schema-characterized metadata, as according to the need expressed in published descriptions of the Semantic Web. Using the extensibility provided by the W3C Recommendation Modularization of XHTML, this specification includes an 'XHTML Augmented Metadata 1.0 DTD' that implements these features. The first two modifications are relatively trivial, in terms of implementation: (1) allow the <meta> element to appear within any block element as metadata about its parent (i.e., any major document component); (2) add an optional href attribute to the <meta> element to allow it to point to any addressable resource. The third modification is to: (3) add a Dublin Core module to XHTML, modifying the content model of the <meta> element to contain its content. [From the post to 'www-rdf-interest@w3.org': "I've been hesitant to announce this since it's not quite finished, but since you asked, here's a specification in the works that describes how to incorporate Dublin Core metadata within XHTML, so that Web pages can be harvested for their subject, author, etc. content. How this might occur is described in section 5.5.3. You'll note that this doesn't put RDF of any flavour into a Web page. That couldn't be validated, which is one of the requirements of the project, and in terms of being globally useful, allowing every author in the world to create their own flavour of metadata isn't a particularly compelling need; we all need to agree on using the same "carrier" with a small number of controlled vocabularies. Dublin Core fits this bill as a very popular way of capturing a subset of the kinds of metadata described in things I've read about the Semantic Web. There's also a section on how to work this with topic maps..."
[May 31, 2001] "An XML Encoding of Simple Dublin Core Metadata." Edited by Dave Beckett, Eric Miller, and Dan Brickley. Dublin Core Metadata Initiative Proposed Recommendation. 2001-04-11 or later. Dublin Core Metadata Initiative Proposed Recommendation. This version supersedes http://dublincore.org/documents/2000/07/14/dcmes-xml/. "The Dublin Core Metadata Element Set V1.1 (DCMES) can be represented in many syntax formats. This document explains how to encode the DCMES in XML, provides a DTD to validate the documents and describes a method to link them from web pages... This document describes an encoding for the DCMES in XML subject to these restrictions: (1) The Dublin Core elements described in the DCMES V1.1 reference can be used; (2) No other elements can be used; (3) No element qualifiers can be used; (4) The resulting XML cannot be embedded in web pages. The primary goal for this document is to provide a simple encoding, where there are no extra elements, qualifiers, optional or varying parts allowed. This allows the resulting data to be validated against a DTD and guaranteed usable by XML parsers. A secondary goal was to make the encoding also be valid RDF which allows the document to be manipulated using the RDF model. We have tried to limit the RDF constructs to the minimum, and the result is a mostly standard header and footer for every document. We acknowledge that there will be further documents describing other encodings for DC without these restrictions however this one is for the simplest possible form. One result of the restrictions is that the encoding does not create documents that can be embedded in HTML pages..."
[March 14, 2001] "An XML Encoding of Simple Dublin Core Metadata." Edited by Dave Beckett, Eric Miller, and Dan Brickley. Dublin Core Metadata Initiative Proposed Recommendation. 2000-12-01 or later. "The Dublin Core Metadata Element Set V1.1 (DCMES) can be represented in many syntax formats. This document explains how to encode the DCMES in XML, provides a DTD to validate the documents and describes a method to link them from web pages." Appendix A contains the DTD for Dublin Core Metadata Element Set 1.1 in XML; Appendix B [Informational] provides an XML Schema for Dublin Core Metadata Element Set 1.1 in XML. Details: "The Dublin Core Metadata Element Set V1.1 (DCMES) can be represented in many syntax formats. This document gives an encoding for the DCMES in XML, provides a DTD to validate the documents and describes a method to link them from web pages. This document describes an encoding for the DCMES in XML subject to these restrictions: (1) The Dublin Core elements described in the DCMES V1.1 reference can be used; (2) No other elements can be used; (3) No element qualifiers can be used; (4) The resulting XML cannot be embedded in web pages. The primary goal for this document is to provide a simple encoding, where there are no extra elements, qualifiers, optional or varying parts allowed. This allows the resulting data to be validated against a DTD and guaranteed usable by XML parsers. A secondary goal was to make the encoding also be valid RDF which allows the document to be manipulated using the RDF model. We have tried to limit the RDF constructs to the minimum, and the result is a mostly standard header and footer for every document. We acknowledge that there will be further documents describing other encodings for DC without these restrictions however this one is for the simplest possible form. One result of the restrictions is that the encoding does not create documents that can be embedded in HTML pages. Please refer to other Dublin Core documents that can describe how to do that. This document is based on previous work such as (1) DTDs for the Dublin Core Element Set [Eric Miller]' Bath Profile Appendix D [Extensible Markup Language (XML) Document Type Definition for Dublin Core Simple]; (3) Museum records transfer DTD ['The use of XML as a transfer syntax for museum records during the CIMI Dublin Core test bed: some practical experiences,' Bert Degenhart Drenth]; (4) CIMI Dublin Core DTD. DTD online, [cache]
[April 21, 2001] "[DRAFT] Namespace Policy for the Dublin Core Metadata Initiative (DCMI)." By Stuart Weibel, Tom Baker, Tod Matola, and Eric Miller. 2001-03-09. Latest version: http://dublincore.org/documents/dcmi-namespace/. "The use of XML namespaces XML-NAMES for formal, machine-processable declarations of metadata entities is a convention intended to support web-addressable concepts that can be shared across applications, and hence promote the possibility of shared semantics. DCMI adopts this convention for the identification of all DCMI terms. This document identifies the policies and procedures associated with the naming of existing DCMI terms and those that will be defined in the future... The namespace of the Dublin Core metadata element set (version 1.1) is: http://purl.org/dc/elements/1.1/. Declarations for individual elements are constructed by adding entity_name, for example: http://purl.org/dc/elements/1.1/title is the web-addressable identifier for one of the 15 elements of the Dublin Core metadata element set. Each of the 15 elements can be so identified. Stability of namespace identifiers for metadata terms is critical to interoperability over time. Thus, the wide promulgation of this set of identifiers dictates that they be maintained to support legacy applications that have adopted them... Official declarations for all additional metadata packages approved by DCMI, including additional elements, qualifiers and domain specific metadata packages, are specified as http://dublincore.org/YYYY/MM/DD/package_identifier#[ term_name]."
[March 30, 2001] "Expressing Qualified Dublin Core in RDF." Draft Version-2001-3-29. By Dublin Core Architecture Working Group. Authors: Stefan Kokkelink and Roland Schwänzl. Supersedes Guidance on expressing the Dublin Core within the Resource Description Framework (RDF). "In this draft Qualified Dublin Core is encoded in terms of RDF, the Resource Description Framework as defined by the RDF Model & Syntax Specification (XML namespace for RDF). RDF is a W3C recommendation. Also RDFS the RDF Schema specification 1.0 is used (XML namespace for RDFS). RDFS is a W3C candidate recommendation. Quite often the notion of URI (Uniform Resource Identifier) is used. The notion of URI is defined by RFC 2396 The notion of URI embraces URL and URN. We also discuss colaboration of qualified DC with other vocabularies and DumbDown. In this paper explicit encodings are provided for classical classification systems and thesauri. Additionally a procedure is discussed to create encodings for more general schemes. One of the majour changes with respect to the data model draft is the more systematic use of RDF Schema. It is understood that all DC related namespace references are currently in final call at the DC Architecture Working Group. They will be fixed in a forthcoming version of the current draft..." For related work, see CARMEN (Content Analysis, Retrieval and MetaData: Effective Networking) and especially CARMEN AP 6: MetaData based Indexing of Scientific Resources.
[March 16, 2001] Extended DumbDown for Dublin Core metadata. From Stefan Kokkelink. Experimental. "I have set up an online demonstration of a (extended) dumb-down algorithm for Dublin Core metadata. There are several examples available, try the E[1-6] buttons. RDF documents using DC properties should be responsible for seeing that for every DC property (or subProperty) a meaningfull literal value can be calculated by the algorithm described below. Documents respecting this algorithm can use any rdfs:subPropertyOf or any additional vocabularies (e.g. for structured values) they want: the algorithm ensures that these documents can be used for simple resource discovery however complex their internal structue may be. Extended DumbDown algorithm: This algorithm transforms an arbitrary RDF graph containing Dublin Core properties (or rdfs:subPropertyOf) in an RDF graph whose arcs are all given by the 15 Dublin Core elements pointing to an 'appropriate literal'..."
Draft Standard Z39.85-200X. The Dublin Core Metadata Element Set. BALLOTING PERIOD: July 1 - August 15, 2000. "Defines fifteen metadata elements for resource discovery in a multidisciplinary information environment. The Dublin Core Metadata Element Set (DCMES) is a standard for cross-domain information resource description. Here an information resource is defined to be anything that has identity, consistent with Internet RFC 2396. For DCMES applications a resource will typically be an electronic document. This standard supersedes Internet RFC 2413, which was the first published version of DCMES...In the element descriptions below, each element has a descriptive label intended to convey a common semantic understanding of the element, as well as a unique, machine-understandable, single-word name intended to make the syntactic specification of elements simpler for encoding schemes. Although some environments, such as HTML, are not case-sensitive, it is recommended best practice always to adhere to the case conventions in the element names given below to avoid conflicts in the event that the metadata is subsequently extracted or converted to a case-sensitive environment, such as XML (Extensible Markup Language) [XML]. Each element is optional and repeatable. Metadata elements may appear in any order. The ordering of multiple occurrences of the same element (e.g., Creator) may have a significance intended by the provider, but ordering is not guaranteed to be preserved in every system. To promote global interoperability, a number of the element descriptions suggest a controlled vocabulary for the respective element values. It is assumed that other controlled vocabularies will be developed for interoperability within certain local domains." See the main document. [cache]
[July 14, 2000] "Using Dublin Core in XML." By Dave Beckett, Eric Miller, and Dan Brickley. 2000-07-14. PURL: http://purl.org/dc/documents/wd/dcmes-xml-20000714.htm. "The Dublin Core Element Set V1.1 (DCES) can be represented in many syntax formats. This document explains how to encode the DCES in XML, provides a DTD to validate the documents and describes a method to link them from web pages. This document describes encoding the DCES in XML subject to these restrictions: (1) The Dublin Core elements described in the DCES V1.1 reference can be used (2) No other elements can be used (3) No element qualifiers can be used (4) The resulting XML cannot be embedded in web pages." [cache]
[December 28, 2000] "The Dublin Core Metadata Initiative: Mission, Current Activities, and Future Directions." By Stuart L. Weibel (OCLC Office of Research) and Traugott Koch (NETLAB).. In D-Lib Magazine [ISSN: 1082-9873] Volume 6 Number 12 (December 2000). With 54 references. "Metadata is a keystone component for a broad spectrum of applications that are emerging on the Web to help stitch together content and services and make them more visible to users. The Dublin Core Metadata Initiative (DCMI) has led the development of structured metadata to support resource discovery. This international community has, over a period of 6 years and 8 workshops, brought forth: (1) A core standard that enhances cross-disciplinary discovery and has been translated into 25 languages to date; (2) A conceptual framework that supports the modular development of auxiliary metadata components; (3) An open consensus building process that has brought to fruition Australian, European and North American standards with promise as a global standard for resource discovery; (4) An open community of hundreds of practitioners and theorists who have found a common ground of principles, procedures, core semantics, and a framework to support interoperable metadata. The 8th Dublin Core Metadata Workshop capped an active year of progress that included standardization of the 15-element core foundation and approval of an initial array of Dublin Core Qualifiers... The DCMI Open Metadata Registry is a prototype for the DCMI registry, and was demonstrated at DC-8 by Eric Miller. This registry is built from the EOR Extensible Open RDF Toolkit, an open source toolkit designed to facilitate the design and implementation of applications based on the W3C's RDF and XML standards. EOR is also being used by the European Commission funded SCHEMAS project. DCMI or an initiative like the SCHEMAS project can use this Extensible Open RDF (EOR) Toolkit to build a registry that reflects policy and implementation decisions about a given application. The software will allow schema designers to discover, navigate and annotate semantics and to understand relationships to other semantics. The prototype supports the construction and management of a database for aggregation, querying, managing and displaying metadata in RDF format. User interfaces for human and machine usage and an improved annotation support are still under development. This software is also a cornerstone of the open source approach to software development in the DCMI, and is available for development (both for commercial and research adaptation) under a liberal open source license. It is hoped that this approach will promote significant community development that will be fed back into the software base for the benefit of all interested parties... The year 2000 marked the beginning of a transition in Dublin Core Metadata Initiative activities. The approval of DC qualifiers provides a finer granularity for resource description, and the work of the DCMI Education working group extends the scope of DCMI semantics to embrace domain specific needs. The emerging work on application profiles suggests the means to further expand into the uncharted territory of mixing namespaces and hybrid schemas that borrow elements from different communities. The DCMI workplan for the year 2001 will embrace a variety of ongoing activities, and some new ones, as well..."
"A Grammar of Dublin Core." By Thomas Baker (GMD -- German National Research Center for Information Technology Scientific Library and Publication Services Schloss Birlinghoven D-53754 Sankt Augustin, Germany). In D-Lib Magazine [ISSN: 1082-9873] Volume 6 Number 10 (October 2000). "Dublin Core is often presented as a modern form of catalog card -- a set of elements (and now qualifiers) that describe resources in a complete package. Sometimes it is proposed as an exchange format for sharing records among multiple collections. The founding principle that 'every element is optional and repeatable' reinforces the notion that a Dublin Core description is to be taken as a whole. This paper, in contrast, is based on a much different premise: Dublin Core is a language. More precisely, it is a small language for making a particular class of statements about resources. Like natural languages, it has a vocabulary of word-like terms, the two classes of which -- elements and qualifiers -- function within statements like nouns and adjectives; and it has a syntax for arranging elements and qualifiers into statements according to a simple pattern. A Pidgin for Digital Tourists. Whenever tourists order a meal or ask directions in an unfamiliar language, considerate native speakers will spontaneously limit themselves to basic words and simple sentence patterns along the lines of 'I am so-and-so' or 'This is such-and-such'. Linguists call this pidginization. In such situations, a small phrase book or translated menu can be most helpful. By analogy, today's Web has been called an Internet Commons where users and information providers from a wide range of scientific, commercial, and social domains present their information in a variety of incompatible data models and description languages. In this context, Dublin Core presents itself as a metadata pidgin for digital tourists who must find their way in this linguistically diverse landscape. Its vocabulary is small enough to learn quickly, and its basic pattern is easily grasped. It is well-suited to serve as an auxiliary language for digital libraries. This grammar starts by defining terms. It then follows a 200-year-old tradition of English grammar teaching by focusing on the structure of single statements. It concludes by looking at the growing dictionary of Dublin Core vocabulary terms -- its registry, and at how statements can be used to build the metadata equivalent of paragraphs and compositions -- the application profile... With an Appendix: Dublin Core and RDF grammar compared. The Resource Description Framework (RDF), a relatively new standard of the World Wide Web Consortium, is emerging as an information model and encoding format of choice for metadata and application profiles that use Dublin Core [W3C 1999, W3C 2000]. RDF is a grammar for expressing relationships among resources located or represented somewhere on the Internet. These relationships are depicted graphically with Directed Labelled Graphs (DLGs), which use arcs (predicates expressing properties) to establish a relationship between multiple nodes (resources). Nodes are seen as subjects or objects depending on the direction of the arrow..."
[February 17, 2001] "Keeping Dublin Core Simple. Cross-Domain Discovery or Resource Description?" By Carl Lagoze (Cornell University). In D-Lib Magazine [ISSN: 1082-9873] Volume 7 Number 1 (January 2001). With 33 references. "Multiple views -- different types of metadata associated with a Web resource -- can facilitate a 'drill-down' search paradigm, whereby people start their searches at a high level and later narrow their focus using domain-specific search categories. For example, the Mona Lisa may be viewed from the perspective of non-specialized searchers, with categories that are valid across domains (who painted it and when?); in the context of a museum (when and how was it acquired?); in the geo-spatial context of a walking tour using mobile devices (where is it in the gallery?); and in a legal framework (who owns the rights to its reproduction?). Multiple descriptive views imply a modular approach to metadata. Modularity is the basis of metadata architectures such as the Resource Description Framework (RDF), which permit different communities of expertise to associate and maintain multiple metadata packages for Web resources. As noted elsewhere, static association of multiple metadata packages with resources is but one way of achieving modularity. Another method is to computationally derive order-making views customized to the current needs of a client. This paper examines the evolution and scope of the Dublin Core from this perspective of metadata modularization. Dublin Core began in 1995 with a specific goal and scope -- as an easy-to-create and maintain descriptive format to facilitate cross-domain resource discovery on the Web. Over the years, this goal of 'simple metadata for coarse-granularity discovery' came to mix with another goal -- that of community and domain-specific resource description and its attendant complexity. A notion of 'qualified Dublin Core' evolved whereby the model for simple resource discovery -- a set of simple metadata elements in a flat, document-centric model -- would form the basis of more complex descriptions by treating the values of its elements as entities with properties ('component elements') in their own right. At the time of writing, the Dublin Core Metadata Initiative (DCMI) has clarified its commitment to the simple approach. The qualification principles [Dublin Core Qualifiers] announced in early 2000 support the use of DC elements as the basis for simple statements about resources, rather than as the foundation for more descriptive clauses. This paper takes a critical look at some of the issues that led up to this renewed commitment to simplicity... Metadata is expensive to create -- especially the more complex varieties -- and the benefits need to be weighed against the costs. The development of a well-scoped qualification model has defined an important niche for the Dublin Core in the larger metadata ecology. It is important to publicize this more prudent approach within the broader community, some of which has been confused over the past few years by mixed messages about Dublin Core and its scope. Equally important for the DCMI is the completion of the supporting documentation -- user guides, encoding guides, etc. -- needed to make the Dublin Core deployable with commonly available web tools. The completion of these tasks will allow the DCMI to free itself from an exclusive focus on the fifteen elements and explore, with partner communities, the roles and interaction of multiple metadata schemes in the Internet Commons..."
[February 17, 2001] "MARC to Dublin Core Crosswalk." Network Development and MARC Standards Office, Library of Congress. February, 2001. "The following is a crosswalk between core MARC 21 bibliographic data elements and elements in the Dublin Core Element Set. It may be used in conversion of metadata from MARC into Dublin Core. Since MARC is richer in data than Dublin Core, it differs from the Dublin Core/MARC Crosswalk in that multiple MARC fields are mapped to a Dublin Core element. The Dublin Core to MARC crosswalk maps a Dublin Core element to a single MARC field. In both crosswalks there are different mappings for Dublin Core simple or qualified. Not all possible MARC fields are included in this mapping, but only those considered useful for broad cross-domain resource discovery. Applications may wish to include other MARC elements that are prevalent in their data but are not listed here, or they may not include all that are listed."
[February 03, 2001] "Application Profiles, Or How to Mix and Match Metadata Schemas." By Makx Dekkers. In Cultivate Interactive Issue 3 (January 29, 2001). With 22 references. ['Makx Dekkers of PricewaterhouseCoopers, Luxembourg describes some recent developments in the area of application profiles and how application profiles are being used, based on experiences in the SCHEMAS project.'] "If you want to define a metadata schema for your electronic resources, you may want to base your work on what others have done. Until some time ago, everybody who needed to define a metadata element set (or schema) to be used for a particular project or collection of resources, invented their own solution. It is becoming apparent that this approach, re-inventing the wheel so to speak, is not the optimal way of working. It is now becoming accepted that it is a good starting point to base the definition of a local schema on work that other people have done. To support this, the SCHEMAS project aims to build an information service where schemas developed in many places around the world can be found. For a start, this information service will begin to solve one of the major problems encountered by metadata schema designers: the difficulty to find out what has happened elsewhere. However, finding out about existing schemas is only a first step towards the ultimate goal: harmonising usage and converging on formal or de-facto standards. As has been identified by the SCHEMAS project from its inception, any particular project or product has specific requirements that cannot be fully met by standards 'straight from the box'. Almost all practical implementations will have to mix and match elements from various schemas and have a potential need to define additional elements of their own. This mechanism of mixing and matching and defining private elements results in what is now called an application profile. Baker, in a 'strawman proposal' to the Dublin Core Registry Working Group defines application profiles as entities that declare which elements from which namespaces underlie the local schema used in a particular application or project. In his view, application profiles 're-use' semantics from namespaces and repackage them for a particular purpose... In his 'strawman proposal' and in subsequent discussions, Baker laid out a number of functional requirements for application profiles. These requirements fall into four categories: (1) Definition of entity classes in the data model that underlies the application, identifying the type or types of resources the application profile schema applies to, e.g. people, Web pages, books, image galleries; (2) Formal declarations of elements and their semantics used by the application, including rules for their usage, e.g. declaring which elements are mandatory, optional, repeatable, which element combinations are allowed or mandated and what allowable formats for the values of elements are; (3) Expression of controlled vocabularies for the value of elements, e.g. specifying which controlled vocabulary, classification scheme or thesaurus may be used as values for a particular element or restricting the allowable values for a particular element to a enumerated set; (4) Human readable information about the application and usage guidance..."
Dublin Core Metadata for Resource Discovery Network Working Group, Request for Comments: 2413.
Dublin Core Generator - "DC-dot, UKOLN's web-based Dublin Core generator and editor provides support for the W3C XHTML 1.0 recommendation."
[November 01, 2000] "Dublin Core: Building Blocks for the Semantic Web. Simplicity and Utility are Keys to the Future of the Web. [An Introduction to Dublin Core.]" By Eric Miller and Stuart Weibel. From XML.com (October 25, 2000). ['You may have heard of the Dublin Core metadata element set before, but who is behind it, and what do they want to achieve? The leaders of the Dublin Core Metadata Initiative explain what they do and where they're headed.'] "The Dublin Core Metadata Element Set (DCMES) can be viewed as the common semantic building block of Web metadata. Its 15 broad categories (elements) are useful for creating simple, easy-to-understand descriptions for most information resources. Most communities need additional semantics to fully describe their resources, however. So, just as simple Lego blocks can be combined to form complex structures, various modules of metadata can be combined to form more complex descriptions. The DCMES is the basic block, but other chunks of metadata can be combined with it to form richer descriptions. The basic element set is intended to capture most of the fundamental descriptive categories necessary to promote effective search and retrieval. Additional building blocks can be created to provide modular chunks of metadata that can be built into richer descriptions for information resources. So, just as Lego blocks of various shapes can be snapped together to form undersea exploration themes, or recombined to create spaceships or medieval castles, chunks of metadata can be combined and recombined to meet the functional requirements of different applications. The Dublin Core Metadata Initiative provides a forum for the definition of semantics, both for a general description core and for subject-specific extensions. How can these vocabularies be integrated into a functional architecture? Dublin Core metadata can be carried in HTML, XML, and RDF. The latter, the Resource Description Framework, builds on the World Wide Web Consortium's (W3C) effort to design an architecture for metadata on the Web. RDF supports many different metadata needs of vendors and information providers. If Dublin Core Metadata Element Set can be thought of as a Lego that is common to many sets, RDF is the engineering standard that enables that satisfying click when the blocks are snapped together. RDF is part of an infrastructure that will support the combination of Dublin Core modules into larger, more expressive metadata structures that will work with one another. Further, applications should be able to mix metadata from other semantic standards expressed in RDF as well. Just as different Lego sets express undersea, outer space or medieval castle themes, RDF can enable snapping together modules that support metadata themes for education, government, or commercial purposes, all working together in the same architecture..."
[November 01, 2000] "Dublin Core in the Wild." By Rael Dornfest and Dale Dougherty. From XML.com (October 25, 2000). ['The recent Dublin Core Metadata Initiative meeting provided an opportunity for O'Reilly Network to discover more about Dublin Core and to explore its relationship with RSS.'] "The eighth meeting of the The Dublin Core Metadata Initiative (DCMI) was held October 4-6 at the National Library of Canada in Ottawa, Canada. Bringing together about 150 participants from 20 countries, DC8 was as much about focusing the future work of this group as it was an opportunity to educate newcomers like us on the work that had already been accomplished. We were there to explore the relationship between RSS and Dublin Core. The Director of DCMI, Stu Weibel of Online Computer Library Center (OCLC), got things started. Weibel was not the only one to mention that the DCMI are a passionate group -- stemming from their conviction that metadata is the key to improving the state of the Web as an information resource. Weibel explained that DCMI started in 1994 at the 2nd World Wide Web Conference, held in Chicago. Its name comes from Dublin, Ohio, home of OCLC, a library computing consortium. The original mission of DCMI was to improve resource discovery on the Web by establishing a minimal set of metadata constructs, and Weibel reaffirmed that mission in his opening talk. He said that DCMI has become an "open consensus-building initiative" dedicated to improving the ways users find things on the Web. While recognizing that DCMI is not the only group working on metadata standardization, Weibel noted that DCMI's approach has always been interdisciplinary, and its focus remains fixed on the Web..."
