Rich descriptive metadata in XML: MODS as a metadata scheme

1. Rich descriptive metadata in XML: MODS as a metadata scheme “MODS, MARC and Metadata Interoperability” ALA Annual 2005 Rebecca Guenther Network Development and MARC Standards Office Library of Congress

2. Overview of presentation • MARC and XML • MODS introduction • Uses • Features • Advantages • MODS relationship to other metadata schemes • MODS Projects MODS, MARC and Metadata Interoperability

3. MARC and XML • Importance of descriptive metadata in current environment • Large investments in MARC systems • Retooling to make use of the flexibility of XML • Libraries may receive records using other metadata schemes in XML • Descriptive metadata may come as part of digital objects • Collaborative use of metadata for access • OAI harvesting • Z39.50 and SRU/SRW MODS, MARC and Metadata Interoperability

4. Evolution of MARC 21 • Need to take advantage of XML • Establish standard MARC 21 in an XML structure • Take advantage of freely available XML tools • Need simpler (but compatible) alternatives • Development of MODS • Need interoperability with different schemas • Assemble coordinated set of tools • Need continuity with current data • Provide flexible transition options MODS, MARC and Metadata Interoperability

5. MARC 21 evolution to XML

6. MARC 21 in XML – MARCXML • MARCXML record • XML exact equivalent of MARC (2709) record • Lossless/roundtrip conversion to/from MARC 21 record • Simple flexible XML schema, no need to change when MARC 21 changes • Presentations using XML stylesheets • LC provides converters (open source) • http://www.loc.gov/standards/marcxml MODS, MARC and Metadata Interoperability

7. What is MODS? • Metadata Object Description Schema • Descriptive metadata standard • Initiative of Network Development and MARC Standards Office at LC • Uses XML Schema language • Originally designed for library applications, but may be used for others • A derivative of MARC MODS, MARC and Metadata Interoperability

8. Potential Uses of MODS • As a rich (but not too rich) XML metadata format for emerging initiatives • SRU/SRW: search and retrieval XML format • METS • to represent metadata for harvesting (OAI) • As a core element set for convergence between MARC and non-MARC XML descriptions • For original resource description in XML syntax that is simpler than full MARC

9. Advantages of MODS • Element set is compatible with existing descriptions in large library databases • Element set is richer than Dublin Core but simpler than full MARC • Language tags are more user-friendly than MARC numeric tags • Hierarchy allows for rich description, especially of complex digital objects • Rich description that works well with hierarchical METS objects

10. Features of MODS • Uses language-based tags • Elements share definitions with equivalents in MARC • Particularly applicable to digital resources • MODS does not assume the use of any specific rules for description • Element descriptions are reused throughout the schema • Some repackaging of redundant elements • Use of XML schema allows for flexibility and availability of freely available tools

11. Title Info Name Type of resource Genre Origin Info Language Physical description Abstract Table of contents Target audience Note Subject Classification Related item Identifier Location Access conditions Extension Record Info MODS high-level elements

12. Status of MODS • Open listserv collaboration of possible implementors, LC coordinated (1st half 2002) • First comment and use period: June – December 2002 • Version 2.0 Feb. 2003-Dec. 2003 • MODS version 3.0 has been stable for over a year; about to issue 3.1 • Registration approved by National Information Standards Organization (NISO) • Recently issued companion for authority metadata (MADS)

13. Relationship to other descriptive schemas? • Compatible with MARC • General purpose: not tied to particular type of material • Other descriptive metadata schemes: • DC (general resource discovery) • EAD (archival; finding aids) • ONIX (publishers) • VRA Core (visual resources) • CSGDM (geospatial) • TEI header (marked up text) MODS, MARC and Metadata Interoperability

14. Differences between MODS and Dublin Core • MODS has structure • Names • Publication information (originInfo) • Related item • Subject • MODS is more compatible with library data • Semantics • Conversions • Relationships between elements • Includes record management (administrative metadata) information MODS, MARC and Metadata Interoperability

15. MARCXML vs. MODS • Music record in MARC http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi?v4=1&DB=local&CMD=010a+85753651&CNT=10+records+per+page • Music record in MARCXML http://www.loc.gov/standards/mods/music-marcxml-record.xml • Music record in MODS http://www.loc.gov/standards/mods/music-mods-record.xml MODS, MARC and Metadata Interoperability

16. LC uses of MODS • Describing electronic resources • AV project, web archiving • Incorporation with XML resources • METS projects for digital resources (e.g. IHAS, Blackmun) • OAI collections • LC offers MODS, MARCXML, DC simple • SRU/SRW: can get records in MODS

17. MINERVA at LC • MINERVA: LC’s web archiving project (based on specific themes) • Exploring issues with born digital resources • MODS used for descriptive metadata • Election 2002 Web archive • Collaboration with Internet Archive, Webarchivist.org • Selective collection of archived sites July-Nov. 2002 • MODS records for each site (multiple captures) • Other collections: 9/11, 107th Congress, War in Iraq, Election 2004

18. Title Name (structured form) Abstract Date captured Genre (value always “Web site”) Physical description (file formats) Identifier (base URL) Language Access conditions/rights management Subject Fields used in Minerva project

21. Election 2002 Web Archive • MODS record in XML • Archived site MODS, MARC and Metadata Interoperability

22. 107th Congress collection Metadata and search page done at LC • 107th Congress Collection search page • 107th Congress Collection browse • Record display MODS, MARC and Metadata Interoperability

23. Iraq War Web Archives • Catalogers input form • Air Force Times record in XML MODS, MARC and Metadata Interoperability

24. I Hear America Singing • Creating METS objects • Use of Fedora digital repository software • MODS used for descriptive metadata • Display derived from METS/MODS objects • I Hear America Singing http://www.loc.gov/ihas MODS, MARC and Metadata Interoperability

28. MODS in IHAS • MODS XML record • METS document with MODS embedded MODS, MARC and Metadata Interoperability

29. A few other MODS projects • MusicAustralia • MODS as exchange format between National Library of Australia and ScreenSoundAustralia • Allows for consistency with MARC data • http://www.musicaustralia.org/ • Many METS based projects • Chopin Early Editions (University of Chicago Library)

30. Directions for MODS • Digital library projects • MODS works well with METS • Allows for description at any hierarchical level • Flexibility of schema may provide richer linking capability than MARC • LC use • Experiment with MODS for large collections of Web sites • Collection level record with link to MODS individual records • Exploring MODS tools for input and searching • Exploring integrating access with other records • Make available via Open Archives Initiative Protocol MODS, MARC and Metadata Interoperability

31. Choosing MODS for descriptive metadata MODS is particularly useful for • compatibility with existing bibliographic data • embedded descriptions in relatedItem • Rich, hierarchical descriptions that work well with METS structural map • “out of the box” schema; can use <extension> for local elements and to bring in external elements from other schemas MODS, MARC and Metadata Interoperability

32. For further information http://www.loc.gov/standards/mods http://www.loc.gov/standards/mets http://www.loc.gov/minerva http://www.loc.gov/ihas