# Presentation: 774258

##  MARCXML, MODS and Dublin Core

- MAVIS Users Conference 2003
- Rebecca Guenther (rgue@loc.gov)
- Library of Congress

## Overview of presentation

- Why MARC in XML
- MARCXML environment
- MODS
- Dublin Core
- Comparisons

## The MARC format

- Markup: data element set
- Semantics: meaning of elements (but content defined by other standards)
- Structure = syntax for communication
- 2709
- MARCXML
- MARC 21: an international descriptive metadata format

## MARCXML evolution

- Need to take advantage of XML
- Establish standard MARC 21 in an XML structure
- 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

## MARC in XML	

- Why make transition to XML?
- To take advantage of emerging tools and systems that function through XML
- To make MARC compatible with new initiatives in the XML environment such as
- ZING (Z39.50 International Next Generation)
- OAI (Open Archives Initiative harvesting)
- METS (Metadata Encoding & Transmission Schema)
- DC (use data from Dublin Core in MARC environment)
- ONIX (use data from ONIX in the MARC environment)

## MARC 21 evolution to XML

- <footer>MAVIS Users

- Nov. 6, 2003

## MARC 21 (2709) record (machine view)

- 	00967cam  2200277 a 4500 001000800000005001700008008004100025020005300229040001800282050002400312082002100336100003000357**245007400387**260004400461300003500505440001200540500002000552650004200572651002500614_x001e_
-      3471394_x001e_19990429094819.1_x001e_931129s1994    wauab         001 0 eng  _x001e_  _x001f_a   93047676 _x001e_  _x001f_a0898863872 (acid-free, recycled paper) :_x001f_c$14.95_x001e_  _x001f_aDLC_x001f_cDLC_x001f_cDLC _x001e_00_x001f_aGV1046.G3_x001f_bG47 1994_x001e_00_x001f_a796.6/4/0943_x001f_220_x001e_1 _x001f_aSlavinski, Nadine,_x001f_d1968-_x001e_**10_x001f_aGermany by bike :_x001f_b20 tours geared for discovery /_x001f_cNadine Slavinski._x001e_**  _x001f_aSeattle, Wash. :_x001f_bMountaineers,_x001f_cc1994._x001e_  _x001f_a238 p. :_x001f_bill., maps ;_x001f_c22 cm._x001e_ 0_x001f_aBy bike_x001e_  _x001f_aIncludes index._x001e_ 0_x001f_aBicycle touring_x001f_zGermany_x001f_xGuidebooks._x001e__x001d_

## 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)
- Standardization allows for communication and standard transformations

## MARC21 (2709) to MARCXML

- <record xmlns="http://www.loc.gov/MARC21/slim">
- 	<leader>00967cam  2200277 a 4500</leader>
- 	<controlfield tag="001">3471394</controlfield>
- 	<controlfield tag="005">19990429094819.1</controlfield>
- 	<controlfield tag="008">931129s1994    wauab         001 0 eng  </controlfield>
- 	<datafield tag="020" ind1=" " ind2=" ">
- 		<subfield code="a">0898863872 (acid-free, recycled paper) :</subfield>
- 		<subfield code="c">$14.95</subfield>
- 	</datafield>
- 	<datafield tag="040" ind1=" " ind2=" ">
- 		<subfield code="a">DLC</subfield>
- 		<subfield code="c">DLC</subfield>
- 		<subfield code="d">DLC</subfield>
- 	</datafield>
- 	<datafield tag="050" ind1="0" ind2="0">
- 		<subfield code="a">GV1046.G3</subfield>
- 		<subfield code="b">G47 1994</subfield>
- 	</datafield>
- 	<datafield tag="082" ind1="0" ind2="0">
- 		<subfield code="a">796.6/4/0943</subfield>
- 		<subfield code="2">20</subfield>
- 	</datafield>
- 	<datafield tag="100" ind1="1" ind2=" ">
- 		<subfield code="a">Slavinski, Nadine,</subfield>
- 		<subfield code="d">1968-</subfield>
- 	</datafield>

## MARCXML record (continued)

- 	**<****datafield**** tag****="****245****"**** ind1****="****1****"**** ind2****="****0****">**
**	****	****<****subfield**** code****="****a****">****Germany by bike :****</****subfield****>**
**	****	****<****subfield**** code****="****b****">****20 tours geared for discovery /****</****subfield****>**
**	****	****<****subfield**** code****="****c****">****Nadine Slavinski.****</****subfield****>**
- 	</datafield>
- 	<datafield tag="260" ind1=" " ind2=" ">
- 		<subfield code="a">Seattle, Wash. :</subfield>
- 		<subfield code="b">Mountaineers,</subfield>
- 		<subfield code="c">c1994.</subfield>
- 	</datafield>
- 	<datafield tag="300" ind1=" " ind2=" ">
- 		<subfield code="a">238 p. :</subfield>
- 		<subfield code="b">ill., maps ;</subfield>
- 		<subfield code="c">22 cm.</subfield>
- 	</datafield>
- 	<datafield tag="440" ind1=" " ind2="0">
- 		<subfield code="a">By bike</subfield>
- 	</datafield>
- 	<datafield tag="500" ind1=" " ind2=" ">
- 		<subfield code="a">Includes index.</subfield>
- 	</datafield>
- 	<datafield tag="650" ind1=" " ind2="0">
- 		<subfield code="a">Bicycle touring</subfield>
- 		<subfield code="z">Germany</subfield>
- 		<subfield code="x">Guidebooks.</subfield>
- 	</datafield>
- </record>

## MARCXML – other tools

- Tagging transformations with XSLT stylesheets
- Name instead of number tags?
- Different language tags for MODS?
- Allows flexibility for display
- Character set transformations
- MARCXML to FRBR tool (for experimentation)
- MARC record validation tool

## What is MODS?

- Metadata Object Description Schema
- Bibliographic element set
- Initiative of Network Development and MARC Standards Office at LC
- Uses XML Schema
- Specifically for library applications, although could be used more widely
- A derivative (and subset) of MARC elements

**Notes:**
Element set: list of elements that can be used; list that must be used; other standards/policies define levels
Semantics=meaning of fields
Syntax: defines Leader, Directory, tags, indicator structure
AACR2-- traditional use, now broadened
Other metadata conent standards can use MARC (e.g. archival rules)

## Why MODS?

- XML (Extensible Markup Language) is the markup for the Web
- Investigating XML as a new more flexible syntax for MARC element set
- Need for rich descriptive metadata in XML but simpler than full MARC, especially for complex digital library objects

## Potential Uses of MODS

- Need for a rich (but not too rich) XML metadata format for emerging initiatives
- as a Z39.50 Next Generation specified format
- as an extension schema to METS (Metadata Encoding and Transmission Standard)
- to represent metadata for harvesting (OAI)
- As an interoperable core for convergence between MARC and non-MARC XML descriptions
- For original resource description in XML syntax
- For packaging metadata with a resource

## Advantages of MODS

- Element set is richer than Dublin Core
- Hierarchy allows for rich description of complex digital objects
- Element set is more compatible with library data than ONIX or DC
- Element set is simpler than the full MARC format (MARCXML is entire format in XML syntax)

## Features of MODS

- Uses language-based tags
- Elements generally inherit semantics of MARC
- Some data has been repackaged; in some cases what is in several data elements in MARC may be brought together into one in MODS
- MODS does not assume the use of any specific cataloging code
- Reuse element descriptions throughout the schema
- Not intended to be a MARC replacement

## Limitations of MODS

- Because it’s a subset of MARC fields, a conversion retains core data and loses other data
- Does not allow for a round-trip mapping to and from MARC
- Content rules are not covered by MODS, although definitions of elements come from MARC

## MARCXML to MODS

- <mods xmlns="http://www.loc.gov/mods/">
- 	**<****titleInfo****><****title****>****Germany by bike : 20 tours geared for discovery /****</****title****></****titleInfo****>**
- 	<name type="personal">
- 		<namePart>Slavinski, Nadine,</namePart>
- 		<namePart type="date">1968-</namePart>
- 		<role>creator</role>
- 	</name>
- 	<typeOfResource>text</typeOfResource>
- 	<publicationInfo>
- 		<placeCode authority="marc">wau</placeCode>
- 		<place>Seattle, Wash. :</place>
- 		<publisher>Mountaineers,</publisher>
- 		<dateIssued>c1994.</dateIssued>
- 		<dateIssued encoding="marc">1994</dateIssued>
- 		<issuance>monographic</issuance>
- 	</publicationInfo>
- 	<language authority="iso639-2b">eng</language>
- 	<physicalDescription><extent>238 p. : ill., maps ; 22 cm.</extent></physicalDescription>
- 	**<****note**** type****="****statement of responsibility****">****Nadine Slavinski.****</****note****>**
- 	<note>Includes index.</note>

## MODS (continued)

- 	<subject authority="lcsh">
- 		<topic>Bicycle touring</topic>
- 		<geographic>Germany</geographic>
- 		<topic>Guidebooks.</topic>
- 	</subject>
- 	<classification authority="lcc">GV1046.G3 G47 1994</classification>
- 	<classification authority="ddc" edition="20">796.6/4/0943</classification>
- 	<relatedItem type="series">
- 		<titleInfo><title>By bike</title></titleInfo>
- 	</relatedItem>
- 	<identifier type="isbn">0898863872 (acid-free, recycled paper) :</identifier>
- 	<identifier type="lccn">93047676</identifier>
- 	<recordInfo>
- 		<recordContentSource>DLC</recordContentSource>
- 		<recordCreationDate encoding="marc">931129</recordCreationDate>
- 		<recordChangeDate encoding="iso8601">19990429094819.1
- 		</recordChangeDate>
- 		<recordIdentifier>3471394</recordIdentifier>
- 	</recordInfo>
- </mods>

## MODS at LC

- Minerva project metadata
- Web archiving project
- OAI metadata server for some American Memory collections
- Allow for richer metadata; choice of DC, MODS or MARCXML
- Incorporation with XML resources
- AV Prototype project; IHAS
- Developing tools for METS and MODS

## MODS Minerva record

- <mods>
-    <titleInfo><title>FranUlmer.com -- Home Page</title></titleInfo>
-    <titleInfo type="alternative"><title>Fran Ulmer, Democratic candidate for Governor, Alaska,  2002</title></titleInfo>
-    <name type="personal"><namePart>Ulmer, Fran</namePart></name>
-    <genre>Web site</genre>
-    <originInfo>
-       <dateCaptured point="start"encoding="iso8601“>20020702
-       </dateCaptured>
-       <dateCaptured point="end" encoding="iso8601">20021203
-       </dateCaptured>
-    </originInfo>
-    <language authority="iso639-2b">eng</language>
-    <physicalDescription>
-       <internetMediaType>text/html</internetMediaType>
-       <internetMediaType>image/jpg</internetMediaType>
-    </physicalDescription>

## MODS Minerva record (continued)

-   <abstract>Web site promoting the candidacy of Fran Ulmer, Democratic...</abstract>
-   <subject><topic>Elections</topic><geographic>Alaska </geographic></subject>
-   <subject><topic>Governors</topic><geographic>Alaska  </geographic><topic>Election</topic></subject>
-   <subject><topic>Democratic Party (AK)</topic></subject>
-   <relatedItem type="host">
-       <titleInfo><title>Election 2002 Web Archive</title></titleInfo>
-       <identifier type="uri">
-         http://www.loc.gov/minerva/collect/elec2002/</identifier>
-   </relatedItem>
-   <identifier type="uri" displayLabel="Active site">http://www.franulmer.com/</identifier>
-   <identifier type="uri" displayLabel="Archived site">http://wayback-cgi1.alexa.com/e2002/*/http://www.franulmer.com/</identifier>
- </mods>

## Slide 23

## Other MODS projects

- MusicAustralia
- MODS as exchange format between National Library of Australia and ScreenSoundAustralia
- Switched from DC-Library application profile
- Descriptive metadata extension schema used with METS for many digital library projects
- University of California Press
- Merges metadata from library catalog and non-MARC metadata from UC Press via MODS
- Schema used with bibliographic citations

## What is the Dublin Core Metadata Element Set?

- Overall governing body: DCMI
- Descriptive metadata
- 15 data elements with semantics (DCMES)
- Syntax is not mandated (but model and usage largely based on RDF)
- Not a system or format
- Does not define content rules

## What uses did the designers expect?

- Resource discovery and retrieval
- Facilitate searching on the Web
- Provide fielded searching
- Provide metadata simultaneously with data
- But may exist as separate record
- Allow inclusion of templates for record creation
- Serves as basis for a fuller record

## Dublin Core Metadata Initiative

- Dublin Core Metadata Element set
- DC Simple
- DC Qualified
- All elements are repeatable, optional, extensible
- Concept of an application profile
- Define content rules (repeatability, required elements)
- Combine elements from different metadata schemes
- Give best practice for an application

## The Dublin Core Metadata Element Set

- Title
- Author or Creator
- Subject and Keywords
- Description
- Publisher
- Contributor
- Date
- Resource Type

- Format
- Resource Identifier
- Source
- Language
- Relation
- Coverage
- Rights Management

- http://dublincore.org/documents/dces

## DC Interoperability Qualifiers

- Set of approved qualifiers, March 2000
- Principles of qualification
- element refinements (refine meaning of element) e.g. alternative (qualifier of title)
- encoding schemes (aid in the interpretation of a value) e.g.LCSH
- Notion of “dumb down”
- Limited adoption
- Difficulty in layering complexity onto simplicity
- Qualifiers expressed as separate elements

## DCMI mission and scope

- Mission of DCMI: to 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

## DC Implementations

- Interdisciplinary and international recognition as the *lingua franca* for resource discovery metadata for electronic resources
- Variety of sectors and subject areas (archives, museums, science, mathematics, libraries, medicine, etc.)
- Government endorsed metadata
- OAI
- Prism
- Adobe

## Dublin Core successes

- International acceptance as the lingua franca of metadata
- Broad adoption across diverse applications
- Hundreds of DC based projects
- Attempts to broaden the initiative to be a focal point for metadata discussions
- Provides a resource description standard for communities that don’t have one

## Dublin Core failures

- Difficulty in defining a clear scope
- Tension between simplicity and complexity
- Lack of content rules, required elements
- Lack of search engine support
- Flat structure cannot be used for complex objects
- Lack of schema standardization
- May imply RDF implementation to fully use
- All implementations require adaptations, limiting interoperability

## Differences between MODS and Dublin Core

- MODS has structure
- Names
- Related item
- Subject
- MODS fits better in library environment
- Semantics
- Conversions
- Relationships between elements
- MODS includes record management information

## Using DC or MODS

- DC simple as a “lowest common denominator” between diverse metadata schemes
- DC for interoperability at coarse level
- Qualified DC still needs work
- Most DC implementations use local adjustments  (resulting in less interoperability)
- XML schema for qualified DC not fully complete
- MODS useful for
- compatibility with existing bibliographic data
- embedded descriptions in relatedItem

## Metadata Crosswalks

- Dublin Core-MARC
- ONIX-MARC
- FGDC-MARC
- MODS-MARC
- UNIMARC-MARC
- GILS-MARC
- http://www.loc.gov/marc/marcdocz.html

**Notes:**
15 elements have been mapped to MARC.

Not an official mapping in other direction; many to one is harder

FGDC: proposal in 1994 to define any elements from CSDGM that didn’t map to a defined MARC field; MARC used for catalog access

SGML DTD for elements in MARC

Need to standardize for interoperation

## For further information

- h_[ttp](http://www.loc.gov/marcxml)__[://www.loc.gov/marcxml](http://www.loc.gov/marcxml)_
- _[http://www.loc.gov/mods](http://www.loc.gov/mods)_
- http://dubincore.org