The Dublin Core Metadata Initiative: Cross-domain resource description and resource discovery OASIS Symposium on Reliable Infrastructures for XML, April 27, 2004, New Orleans, LA William E. Moen School of Library and Information Sciences Texas Center for Digital Knowledge University of North Texas Denton, TX 72603

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 2 Road map Some terminology Overview of Dublin Core Selected implementations and applications

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 3 Terminology Metadata The result of processes (manual or automatic) performed on an object, where the result is a representation or derivative of the salient features of the object Descriptive information about an object or resource whether it be physical or electronic Can serve many and multiple purposes Resource description Metadata used to create resource descriptions, e.g., library catalog records, of information objects Resource discovery Metadata used to assist people in finding, identifying, selecting, and accessing information objects

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 4 Terminology Information organization The processes and practices of describing and representing information objects (containers and content), and identifying the connections and relationships between the objects and the people responsible for their creation and/or production. Purpose of information organization These processes and practices serve users by assisting them to identify, locate, access, retrieve, and make judgments about information in response to their information needs.

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 5 Dublin Core Metadata Initiative Dublin Core Metadata Initiative (DCMI) An organization dedicated to fostering the widespread adoption of interoperable metadata standards and promoting the development of specialized metadata vocabularies for describing resources to enable more intelligent resource discovery systems Mission Make it easier to find resources using the Internet through the following activities: Developing metadata standards for discovery across domains Defining frameworks for the interoperation of metadata sets Facilitating the development of community- or disciplinary-specific metadata sets that are consistent with items 1 and 2

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 6 Dublin Core Metadata Element Set Dublin Core Metadata Element Set (DCMES) A set of 15 descriptive semantic definitions A core set of elements that could be shared across disciplines or within any type of organization needing to organize and classify information Three formally endorsed versions the Dublin Core Metadata Element Set, version 1.1: ISO Standard (February 2003) NISO Standard Z (September 2001) CEN Workshop Agreement CWA (March 2000) Internet RFC 2413 (September 1998): first published version of the Dublin Core; superseded by the above three standards

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 7 Design goals for DCMES Simplicity of creation and maintenance Define a small and simple metadata element set to allow a non- specialist to create simple descriptive records for information resources easily and inexpensively while providing for effective retrieval of those resources in the networked environment. Commonly understood semantics Provide a common set of elements, the semantics of which are universally understood and supported. International scope Involve representatives from virtually every continent to ensure the development of the standard considers the multilingual and multicultural nature of the electronic information universe. Extensibility Provide mechanisms for extending the DC element set for additional resource discovery needs.

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 8 The 15 elements Type (Resource Type) Format (Format) Identifier (Resource Identifier) Source (Source) Language (Language) Relation (Relation) Coverage (Coverage) Rights (Rights Management) Title (Title) : Creator (Creator) Subject (Subject and Keywords) Description (Description): Publisher (Publisher) Contributor (Contributor) Date (Date) All elements are optional and repeatable

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 9 Three components for metadata Elements & Semantics Definitions for the content of the elements, e.g., what is a title, creator, etc. Focus of DCMES Content Rules – Guidelines and direction for inputting the content, e.g., what to capitalize, order of elements, etc. DCMES guidelines available Syntax Rules for structuring and expressing the elements for machine processing DCMES is syntax independent

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 10 Element name and semantics Element Name: Title Label: Title Semantics: A name given to the resource. Comment: Typically, Title will be a name by which the resource is formally known. Element Name: Creator Label: Creator Semantics: An entity primarily responsible for making the content of the resource. Comment: Examples of Creator include a person, an organization, or a service. Typically, the name of a Creator should be used to indicate the entity.

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 11 DC qualifiers To extend and refine the 15 elements Two categories of qualifiers: Element Refinement – These qualifiers make the meaning of an element narrower or more specific. A refined element shares the meaning of the unqualified element, but with a more restricted scope. 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.

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 12 DCMI Terms Authoritative specification of all metadata terms related to DC, including elements, element refinements, encoding schemes, vocabulary terms Maintained by the DC Usage Board Contained in the DCMI Metadata Registry DC ElementElement RefinementsElement Encoding Schemes DateDateCreated Valid Available Issued Modified Date Copyrighted Date Submitted DCMI Period W3C-DTF

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 13 Syntax DCMI avoided the syntax wars But interoperability? Now provides specifications for encoding DC simple and DC qualified in: HTML elements XML according to DCMES XML schemas RDF according to DCMES RDF schemas

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 14 Application profiles Consist of data elements drawn from one or more namespace schemas combined together by implementors and optimised for a particular local application. Application profiles are useful as they allow the implementor to declare how they are using standard schemas Characteristics: May draw on one or more existing namespaces Introduce no new data elements May specify permitted schemes and values Can refine standard definitions Application profiles enable implementors “to share information about their schemas in order to inter-work with wider groupings…. Communities can start to align practice and develop common approaches by sharing their application profiles.” From Heery and Patel, 2000

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 15 Implementations and applications Gateway to Educational Materials improve the organization and accessibility of collections of educational materials Monticello Electronic Library DC used to provide semantic interoperability between several databases of electronic media and record types open.gov.uk First entry point to UK public sector information on the internet, uses the Dublin Core RDF vocabulary to describe each of the resources available on the site Environment Australia Utilizes DC for its Web metadata and internal searches

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 16 Implementations and applications Library Application Profile Clarifies the use of DC in libraries and library-related applications and projects Open Archives Initiative Protocol for Metadata Harvesting Uses DC simple for exposing metadata for harvesting Search and Retrieve Web Service An XML-based protocol that uses DC as one of the XML schemas to transfer information from database to client

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 17 Metadata packages and METS Metadata Encoding and Transmission Standard (METS) A digital library standard for encoding descriptive, administrative, and structural metadata Expressed using the XML schema language Dublin Core is not intended to displace any other metadata standard. Rather it is intended to co-exist — often in the same resource description — with metadata standards that offer other semantics. It is fully expected that descriptive records will contain a mix of elements drawn from various metadata standards, both simple and complex. from ANSI/NISO Z39.85

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 18 METS structure METS Header: Contains metadata describing the METS document itself Descriptive Metadata: May point to descriptive metadata external to the METS document or contain internally embedded descriptive metadata, or both. Administrative Metadata: Provides information regarding how the files were created and stored, intellectual property rights, etc. File Section: Lists all files containing content which comprise the electronic versions of the digital object. Structural Map: Outlines a hierarchical structure for the digital library object, and links the elements of that structure to content files and metadata that pertain to each element. Structural Links: Records the existence of hyperlinks between nodes in the hierarchy outlined in the Structural Map. Behavior: A behavior section can be used to associate executable behaviors with content in the METS object

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 19 DC & Admin MD in METS document Alice's Adventures in Wonderland Lewis Carroll between 1872 and 1890 McCloughlin Brothers text image/tiff LZW NYU Press

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 20 Summary Metadata is critical for: Resource description Resource discovery Management of information resources DCMI provides international forum for identifying problems, developing understanding, and proposing solutions. DCMES provides metadata solutions For simple resource description that can be extended for richer resource representations For interoperability of metadata through a system of common semantics and prescribed syntaxes For expressing queries using common search concepts across domains

Moen OASIS Symposium on Reliable Infrastructures for XML--April 27, New Orleans 21 References Dublin Core Metadata Initiative  ANSI/NISO Z : The Dublin Core Metadata Element Set  DCMI Frequently Asked Questions  Using Dublin Core (D. Hillmann)  DCMI Schemas (XML and RDF)  Application Profiles: Mixing and Matching Metadata Schemas (R. Heery and M. Patel)  Dublin Core Projects 