OCLC Online Computer Library Center Metadata Standards Eric

OCLC Online Computer Library Center Metadata Standards Eric Childress OCLC FEDLINK OCLC Users Group Meeting Washington, DC November 18, 2003

Overview Fundamentals – Types of metadata – Document mark-up languages & character encodings Meta. Map Metadata formats: – – MARC, MODS DC, ONIX TEI, EAD, METS, MIX RDF, FGDC, COSATI

Fundamentals 5 types of metadata Descriptive – Title, author, summary, topic, etc. Technical & Structural – File size, software needed, file type(s), presentation instructions, etc. Administrative (a. k. a. “meta-metadata”) – Record number, record date, record source, etc. Rights – Copyright ownership, use privileges, etc. Management – [Typically by/for owning agency]: price paid, circulation restrictions, etc.

Fundamentals Markup languages: – Address the structure of a document – Convey instructions to software that will process text to: • Index the text for searching • To render the text (e. g. , for screen display or print) • Transform the text (e. g. , for a voice synthesizer) for some output device(s) – The markup is generally invisible to end-users Extensible Markup Language (XML): – XML is a metalanguage • Agencies define their own XML to suit their task – By creating Document Type Definitions (DTDs) or XML schema – Data is separate from presentation instructions • Presentation instructions go in a style sheet – Offers just the right mix of flexibility and structure

Fundamentals Character Encodings Character encoding: – Used for communicating text characters in a computing environment – Hundreds of character encoding standards exist – Character conversion is complex and expensive Unicode: – A single, “comprehensive” global encoding standard – Includes characters from scripts of all major modern, most minor, and selected ancient languages

Meta. Map http: //mapageweb. umontreal. ca/turner/meta/english/metamap. html

MARC 21 (ISO 2709) – ISO 2709 -based metadata communications protocol – Choice of two character encoding options: • MARC 8 (ASCII, ANSEL, selected ISO, EACC) • Unicode (limited to equivalents of MARC 8 repertoire) – XML expression is now also an option – Maintenance agency: Library of Congress w/ NLC, BL Strengths: • • Well-maintained, mature standard Widely adopted by library communities Large universe of MARC 21 records available Wide choice of software vendors Weaknesses (in the present & future): • • Virtually unused outside of libraries Limits on field and record size Restricted range of scripts supported Limited ability to convey complex relationships, hierarchy, attributes at tag/subfield level

MODS Metadata Object Description Schema (MODS) – Essentially MARC 21 recast in an XML-native framework • Text-based tags rather than numeric ones, • Selected clusters of related MARC 21 attributes condensed into single MODS element – MARC 21 readily converts to MODS, but you can’t do a lossless reverse conversion of MODS to MARC 21 – Maintenance agency: Library of Congress Value of MODS: – A rich, library-oriented XML metadata schema – Optimized for from-MARC conversion of legacy records – Well-suited as a metadata format for OAI harvesting Applications of MODS: – LC planning to convert 100 K American Memory records – Minerva project, U of Chicago Press, California Digital Library, others using or planning to use for records for web sites, e-texts. – Open. Office Bibliographic Project

MARC 21 & MODS Feature MARC 21 Unicode MARC XML MARC Slim MODS Structure ISO 2709 XML XML Encoding MARC 8 Unicode Repertoire of scripts JACKPHY Unicode lossless Conversion from MARC 21 Conversion to MARC 21 lossless minimal lossless lossless? minor loss OCLC DCPS · Bibliographic OCLC R · Authority OCLC R x · Classification x OCLC R R OCLC R x · Community x x · Holdings OCLC x x x

Dublin Core Metadata Element Set – ISO 15836: 2003(E) The Dublin Core metadata element set – A standard for cross-domain resource description • Designed primarily to support discovery and retrieval – Defines semantics but not syntax (i. e. container) – Choice of simple or qualified DC – Maintenance agency: Dublin Core Metadata Initiative (DCMI) hosted by OCLC Research Value of Dublin Core: – Simplicity, extensibility, interoperability – Worldwide adoption (DCMES translated into 20+ languages) – Usable as crosswalk between major metadata standards Applications of Dublin Core: – Open Archives Initiative (OAI) mandates DC metadata – Wide variety of extended versions in use: • In digital library, archives, museums projects • By e-government programs (AU, CA, DK, FI, IE, NZ, UK) – OCLC usage: Connexion, DCPS, Content. DM, Research

ONIX International (Online Information Exchange): – Standard data exchange format for publishers & jobbers • Based on EPICS (EDIt. EUR Product Information Communication Standards) – For representing and communicating book industry product information in electronic form • Offers two levels of richness (level 1 & level 2) – XML schema with Unicode encoding – Maintenance agency: EDIt. EUR working with input from the Book Industry Communication (BIC) and the Book Industry Study Group (BISG) Value of ONIX: – Meets needs of publishers, jobbers, retail sellers for: • Easier access to richer book data (including bibliographic data, cover art, blurbs, TOCs, UPC data, and much more) • An inexpensive-to-implement common data exchange format Applications of ONIX: – Primarily oriented towards publishers, jobbers, retailers • Most major players (Amazon, Baker & Taylor, etc. ) now using/supporting ONIX – Some interest by libraries & ILS vendors in ONIX

TEI Text Encoding Initiative (TEI): – – For complex markup of literary texts Both SGML & XML DTDs available TEI “header” (TEIH) can be used as a metadata record Maintenance agency: TEI Consortium: • TEI Consortium has executive offices in Bergen, Norway, and is hosted at four university sites worldwide: the Univ. of Bergen, Brown Univ. , Oxford Univ. , and the Univ. of Virginia • Maintains “P 4” Guidelines for Electronic Text Encoding and Interchange Value of TEI: – Designed to meet the needs of scholarly research community (esp. in the humanities) for a variety of activities including: • Adding in-line academic commentary in e-texts • As an aid to research by supporting special indexing points, etc. Applications of TEI: – Widely used by major humanities electronic text collections such as CETH, UVa e-text center, many others.

EAD Encoded Archival Description (EAD) – A format for expressing electronic archival finding aids – EAD DTD (Version 2002) is designed to function as both an SGML and XML DTD – Maintained jointly by the Library of Congress and the Society of American Archivists (SAA) Value of EAD: – Effectively an organized presentation of a collection of documents (typically in an archive or manuscript collection) • EAD header carries metadata for the finding aid • Provides for simple or complex mark-up to support varying levels of indexing • Well-suited for interweaving narrative with links to specific objects in a collection (either directly to the object or via a record for the object that may link to the object). Applications of EAD: – Conversion of existing paper finding aids to electronic form – Widely used by academic institutions and archives in North America – RLG Archival Resources database host copies of many EADs

METS Metadata Encoding and Transmission Standard (METS) – A standard “shell” for encoding data essential for retrieving, preserving, and serving up digital resources • Six modules define descriptive, administrative, structural, rights and other metadata • Some parts of a METS object may be external (e. g. , a MODS record for the descriptive metadata) – Maintenance agency: Library of Congress Value of METS: – Need for METS identified at DLF metadata experts meetings • Varied local approaches to non-descriptive metadata not scaling well & offering little interoperability between agencies – Offers a standard mode for object “packaging” for preservation, institutional repositories, other activities Applications of METS: – LC: planning to use with selected moving images, audio recordings, folk life mixed media collections – OCLC DCPS, RLG, Harvard, Stanford, UC Berkeley, National Library of Wales exploring or using for variety of projects

MIX Metadata for Images in XML (MIX) – XML schema for a set of technical data elements required to manage digital image collections – Format for interchange and/or storage of the data specified in the NISO Draft Standard Data Dictionary: Technical Metadata for Digital Still Images (version 1. 2) – Still in early development and testing phases – Collaboration of: Library of Congress and NISO Technical Metadata for Digital Still Images Standards Committee Value of MIX: – Provides a common XML schema for expressing technical data particular to still and moving digital images – Can be used with other schema such as METS and MODS as part of a comprehensive approach to managing and preserving digital images Applications of MIX: – OCLC DCPS, LC, others planning or testing – MIX still in nascent stage of development and testing

Summary DC ONIX TEI EAD METS MIX Structure XML XML XML Encoding Unicode Unicode Repertoire of scripts Unicode Unicode Lossiness varies Minimal loss Header only - lossy Minimal loss Some ONIXonly data may be lost Header only – lossless Simple description for discovery & retrieval Publisher product info exchange Markup of scholarly Etexts Markup of electronic finding aids Shell with technical data Technical data for digital images e-Govt, Libraries, Museums, Archives, Publishers, Jobbers Humanities scholars Archives, Libraries DCMI Editeur TEI Consortium LC w/ SAA LC LC Conversion from MARC 21 Conversion to MARC 21 Chief purpose Primary user base Maintenance agency

RDF Resource Description Format (RDF) – Graphing theory (i. e. arcs and nodes)-influenced, XML syntax-based metalanguage for expressing metadata about web resources – Designed to convey metadata for machine consumption (raw RDF is not very human-readable) – Fundamental building block of RDF is the triple (subject + predicate + object) – Maintained by the W 3 C; RDF specification under revision Value of RDF: – A subject of debate (typically RDF vs. XML)! – Pro: Model-based expression of metadata critical to the Semantic Web (i. e. derived connections); more flexible, scalable and forgiving standard than XML – Con: RDF carries unneeded processing overhead vs. XML; RDF specification has too many flaws; few use RDF Applications of RDF: – Open Directory Project, selected software (e. g. , Siderean) – OCLC Connexion exports Dublin Core in RDF/XML

CSDGM (a. k. a. FGDC) Content Standard for Digital Geospatial Metadata (CSDGM) [better known as “FGDC”] – CSDGM Version 2 - FGDC-STD-001 -1998 – Defines a common set of terminology and definitions for the documentation of digital geospatial data – Maintained by Federal Geographic Data Committee (FGDC) [an interagency committee] – Crosswalk of FGDC to ISO 19115: 2003(E) Geographic information Metadata available; ANSI technical amendment for ISO-FDGC harmonization in progress Value of FGDC: – Provides common standard for publishing metadata about geospatial resources – Widely used by government and business – Many systems and applications support the standard Applications of FGDC: – Adopted or usable by major geospatial agencies in West. – Usefulness extended with profiles (e. g. Biological Data)

COSATI Committee on Scientific and Technical Information (COSATI) – Cataloging rules and record format for the descriptive cataloging of technical reports and similar documents – Field tags are alpha strings (not numerical like MARC) – Related COSATI subject category list can be used – Owned by CENDI (the Commerce, Energy, NASA, Defense Information Managers Group) [successor to COSATI] Value of COSATI: – Supports straightforward capture of useful metadata for scientific and technical information Applications of COSATI: – Used by a number of science/technical and defense U. S. federal agencies – Small number of library systems (e. g. , SIRSI) support COSATI record import/export – COSATI can be converted to MARC if desired

OCLC Online Computer Library Center Questions

Links Dublin Core: http: //www. dublincore. org EAD: http: //www. loc. gov/ead FGDC: http: //www. fgdc. gov/metadata/meta_stand. html MARC 21: http: //lcweb. loc. gov/marcdocz. html MARCXML: http: //www. loc. gov/marcxml. html METS: http: //www. loc. gov/standards/mets MIX: http: //www. loc. gov/standards/mix MODS: http: //www. loc. gov/standards/mods ONIX: http: //www. editeur. org/onix. html RDF: http: //www. w 3. org/RDF TEI: http: //www. tei-c. org OCLC Research: http: //www. oclc. org/research