1. FEDLINK OCLC Users Group Meeting
                                                      
Metadata Standards
Eric Childress
OCLC
Comments, corrections, suggestions are welcome. Please contact the author via
Washington, DC
November 18, 2003
FEDLINK OCLC Users Group Meeting

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

3. Fundamentals Descriptive Technical & Structural
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.

4. Fundamentals Markup languages 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

5. Fundamentals Character encoding: Unicode: Character Encodings
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

6. MetaMap http://mapageweb.umontreal.ca/turner/meta/english/metamap.html
There are many, many standards. This presentation only discusses a select few…

7. MARC 21 MARC 21 (ISO 2709) Strengths:
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
MARC 21 is well known to all of you, but it may be helpful to review some key points and new developments before looking at non-MARC standards
More info:

8. MODS Metadata Object Description Schema (MODS) Value of 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 100K 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.
OpenOffice Bibliographic Project
MODS is essentially an XML rendering of MARC’s content, but unlike MARC XML, the tagging is text rather than numeric.
OpenOffice Bibliographic Project:
Open Office Bibliographic Project:
MODS also simplifies some aspects of MARC

9. MARC 21 & MODS Feature MARC 21 MARC 21 Unicode MARC XML MARC Slim MODS
Structure
ISO 2709
XML
Encoding
MARC 8
Unicode
Repertoire of scripts
JACKPHY
Conversion from MARC 21
lossless
minimal loss
Conversion to MARC 21
lossless?
minor loss
·        Bibliographic
OCLC
OCLC R
OCLC DCPS
·        Authority x
·        Classification
·        Community
·        Holdings
MARC XML could potentially be used as follows:
for representing a complete MARC record in XML
as an extension schema to METS (Metadata Encoding and Transmission Standard)
to represent metadata for OAI harvesting
for original resource description in XML syntax
for metadata in XML that may be packaged with an electronic resource
Some MARC XML advantages are:
The schema supports all MARC encoded data regardless of format
The MARC XML framework is a component-oriented, extensible architecture allowing users to plug and play different software pieces to build custom solutions
Limitations of MARC XML:
Validation with the MARC XML schema is accomplished via a software tool. This software, external to the schema, will provide three possible levels of validation: (1) Basic XML validation according to the MARC XML Schema; (2) Validation of MARC21 tagging (field and subfield); (3) Validation of MARC record content, e.g., coded values, dates, and times.
“MARC slim” (xmlns=" – a simple validation approach
Added note: UNIMARC and XML:
Ministère de la culture et de la communication (France), Board of Research and Technology is developing
BiblioML DTD for converting UNIMARC to XML
Conversion tools

10. Dublin Core DCMES also issued as NISO Z39.85
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, ContentDM, Research
DCMES also issued as NISO Z39.85

11. ONIX
ONIX International (Online Information Exchange):
Standard data exchange format for publishers & jobbers
Based on EPICS (EDItEUR 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: EDItEUR 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
ONIX is a new standard built by the publishing community. It’s designed to convey a variety of descriptive metadata, but also business-related metadata and important auxiliary objects like image files of book cover art
The goal of ONIX is to standardize the transmitting of product information so that wholesalers, retailers and others in the supply chain will all be able to accept information that is transferred electronically in ONIX International format

12. 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 “P4” 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.
TEI is an e-text markup schema tailor-made for humanities scholars.

13. 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
                                                                                                                                                                                                                                                                 
EAD is a standard jointly owned by LC and SAA that provides a format for expressing collection-level variety information in the form of electronic finding aids.

14. METS Metadata Encoding and Transmission Standard (METS) Value of 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
METS is a new standard designed to capture and convey non-descriptive metadata as well as descriptive metadata.
It has been has been developed in response to LC’s own burgeoning digital collection needs with the aid of insight from Digital Library Federation through information the DLF has gathered from its members
Useful presentation (2003):

15. MIX Metadata for Images in XML (MIX) Value of 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
MIX is a very new metadata standard and has been developed by LC with the help of NISO, and is based in large part on NISO’s work on developing technical metadata standards for images.

16. Summary DC ONIX TEI EAD METS MIX Structure XML Encoding Unicode
XML
Encoding
Unicode
Repertoire of scripts
Conversion from MARC 21
Lossiness varies
Minimal loss
Header only - lossy
Header only - lossy
Conversion to MARC 21
Some ONIX-only data may be lost
Header only – lossless
Header only – lossless
Chief purpose
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
Primary user base
e-Govt, Libraries, Museums, Archives,
Publishers, Jobbers
Humanities scholars
Archives, Libraries
Maintenance agency
DCMI
Editeur
TEI Consortium
LC w/ SAA LC

17. RDF Resource Description Format (RDF) Value of 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 W3C; 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
Specification and useful resources:
Open Directory:

18. CSDGM (a.k.a. FGDC)
Content Standard for Digital Geospatial Metadata (CSDGM) [better known as “FGDC”]
CSDGM Version 2 - FGDC-STD
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)

19. 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
COSATI subject category list based on US Engineers Joint Council Thesaurus of Engineering and Scientific Terms & itself now the basis for the SIGLE Subject Category List

20. Questions

21. Links Dublin Core: http://www.dublincore.org
EAD:
FGDC:
MARC 21:
MARCXML:
METS:
MIX:
MODS:
ONIX:
RDF:
TEI:
OCLC Research: