OCLC/RLG Working Group OCLC/RLG Working Group onon

Metadata for Digital Metadata for Digital PreservationPreservation

Brian LavoieBrian Lavoie

Office of ResearchOffice of Research

OCLC Online Computer Library Center, OCLC Online Computer Library Center, Inc.Inc.

Information Infrastructures for Digital Information Infrastructures for Digital PreservationPreservation

December 6, 2000December 6, 2000

Road MapRoad Map

• BackgroundBackground

• ObjectivesObjectives

• White PaperWhite Paper

• Future ActivityFuture Activity

BackgroundBackground

• March 2000:March 2000:– OCLC and RLG announced commitment to collaborate OCLC and RLG announced commitment to collaborate

on identifying and supporting best practices for long-on identifying and supporting best practices for long-term retention of digital objectsterm retention of digital objects

– Facilitate consensus-building among stakeholdersFacilitate consensus-building among stakeholders

• Collaboration in two areas:Collaboration in two areas:– Attributes of digital archive for research repositoriesAttributes of digital archive for research repositories

– Preservation metadata for long-term retention of digital Preservation metadata for long-term retention of digital objectsobjects

ObjectivesObjectives

• White Paper:White Paper: describe current practice/thinking describe current practice/thinking on the use of metadata to support digital on the use of metadata to support digital preservationpreservation

• Working Group:Working Group: bring together leading experts to bring together leading experts to review existing practices, share expertise, and review existing practices, share expertise, and identify areas for consensus-buildingidentify areas for consensus-building

• Comprehensive metadata framework:Comprehensive metadata framework: to support to support broad range of digital preservation activitiesbroad range of digital preservation activities

Working Group ParticipantsWorking Group Participants

• Planning Committee:Planning Committee:

Robin Dale (RLG)Robin Dale (RLG) Meg Bellinger (OCLC)Meg Bellinger (OCLC)

Brian Lavoie (OCLC)Brian Lavoie (OCLC) Nancy Elkington (RLG)Nancy Elkington (RLG)

Ed O’Neill (OCLC)Ed O’Neill (OCLC)

• Members:Members:

Michael AlexanderMichael Alexander Oya RiegerOya Rieger

Michael DayMichael Day Kelly RussellKelly Russell

Julia FosterJulia Foster Colin WebbColin Webb

Rebecca GuentherRebecca Guenther Robin WendlerRobin Wendler

Bernard HurleyBernard Hurley Titia van der WerfTitia van der Werf

Catherine Lupovici Catherine Lupovici

Preservation Metadata White Preservation Metadata White

PaperPaper • Define and illustrate preservation metadata for digital Define and illustrate preservation metadata for digital

objectsobjects

• High-level requirements for broadly applicable High-level requirements for broadly applicable preservation metadata frameworkpreservation metadata framework

• Open Archival Information System reference modelOpen Archival Information System reference model

• Review existing preservation metadata element sets:Review existing preservation metadata element sets:– CEDARS, National Library of Australia, NEDLIB, HarvardCEDARS, National Library of Australia, NEDLIB, Harvard

• Identify:Identify:– starting points for consensus buildingstarting points for consensus building– issues for working group to address issues for working group to address

Preservation Metadata for Preservation Metadata for

Digital ObjectsDigital Objects Preservation metadata may be used to:Preservation metadata may be used to:– store technical information that supports store technical information that supports

preservation decisions and actionpreservation decisions and action

– document preservation action taken (e.g., migration document preservation action taken (e.g., migration or emulation)or emulation)

– record effects of preservation strategiesrecord effects of preservation strategies

– ensure authenticity of digital resources over timeensure authenticity of digital resources over time

– note information about collection management and note information about collection management and management of rightsmanagement of rights

(National Library of Australia)(National Library of Australia)

High-Level RequirementsHigh-Level Requirements

• Comprehensive metadata frameworkComprehensive metadata framework– Addresses all aspects of preservation processAddresses all aspects of preservation process

• Structured approach:Structured approach:– Metadata fits into broader conceptual framework for complete digital Metadata fits into broader conceptual framework for complete digital

archiving systemarchiving system

– Metadata is complementary to the functional components/processes of Metadata is complementary to the functional components/processes of the archivethe archive

• Applicable to broad range of:Applicable to broad range of:– Digital object typesDigital object types

– Digital archiving activitiesDigital archiving activities

– Institutions (libraries, archives, museums, etc.) Institutions (libraries, archives, museums, etc.)

Open Archival Information Open Archival Information SystemSystem

• Consultative Committee for Space Data SystemsConsultative Committee for Space Data Systems

• OAIS reference model (May 1999):OAIS reference model (May 1999):– conceptual framework for digital archiveconceptual framework for digital archive– draft ISO standarddraft ISO standard

• Establishes terminology and conceptsEstablishes terminology and concepts

• Identifies key functional components and processesIdentifies key functional components and processes

• Proposes information model for digital objects and Proposes information model for digital objects and associated metadataassociated metadata

• Informs many current digital archiving initiativesInforms many current digital archiving initiatives

OAIS Information ModelOAIS Information Model

ArchivalArchivalInformationInformation

PackagePackage

ContentContentInformationInformation

PreservationPreservationDescriptionDescriptionInformationInformation

PackagingPackagingInformationInformation

DescriptiveDescriptiveInformationInformation

ContentContentInformationInformation

PreservationPreservationDescriptionDescriptionInformationInformation

OAIS Information TypesOAIS Information TypesContent Information:Content Information:

– Digital ObjectDigital Object– Representation Information:Representation Information: facilitates rendering, understanding, and facilitates rendering, understanding, and

interpretation of object’s contentinterpretation of object’s content• format specification, data structureformat specification, data structure

Preservation Description Information:Preservation Description Information:– Reference:Reference: uniquely identifies object (internal/external) uniquely identifies object (internal/external)

• ISBN, URNISBN, URN

– Provenance:Provenance: documents history of digital object documents history of digital object• origin, chain of custody, preservation actions and effectsorigin, chain of custody, preservation actions and effects

– Context:Context: relationship of digital object to its environment relationship of digital object to its environment• why it was created, relation to other objectswhy it was created, relation to other objects

– Fixity:Fixity: authentication/validation authentication/validation• checksum, digital signaturechecksum, digital signature

Existing Preservation Existing Preservation

Metadata DraftsMetadata Drafts • CEDARS (2000)CEDARS (2000)

““Draft Specification: CEDARS Preservation Metadata Elements”Draft Specification: CEDARS Preservation Metadata Elements”

http://www.leeds.ac.uk/cedars/MD-STR~5.pdfhttp://www.leeds.ac.uk/cedars/MD-STR~5.pdf

• National Library of Australia (1999)National Library of Australia (1999)““Preservation Metadata for Digital Collections: Exposure Draft”Preservation Metadata for Digital Collections: Exposure Draft”

http://www.nla.gov.au/preserve/pmeta.htmlhttp://www.nla.gov.au/preserve/pmeta.html

• Networked European Deposit Library (2000)Networked European Deposit Library (2000)““Metadata for Long Term Preservation”Metadata for Long Term Preservation”

http://www.kb.nl/coop/nedlib/results/preservationmetadata.pdfhttp://www.kb.nl/coop/nedlib/results/preservationmetadata.pdf

• Harvard (2000)Harvard (2000)““Depositing Objects and Object Metadata to the DRS”Depositing Objects and Object Metadata to the DRS”

limited distributionlimited distribution

Notes on Element SetsNotes on Element Sets

CEDARS:CEDARS:– Explicitly adopts structure and terminology of OAIS Explicitly adopts structure and terminology of OAIS

information modelinformation model– Metadata elements for an archival information Metadata elements for an archival information

packagepackage

National Library of Australia:National Library of Australia:– Data output model: “information we want out of a Data output model: “information we want out of a

metadata system”metadata system”– Does not follow OAIS explicitly, but can be mappedDoes not follow OAIS explicitly, but can be mapped

Notes on Element Sets … Notes on Element Sets … ContinuedContinued

NEDLIB:NEDLIB:

– Core metadata essential for preservation managementCore metadata essential for preservation management

– Explicitly adopts OAIS structure and terminologyExplicitly adopts OAIS structure and terminology

– Focuses on “preservation metadata, not metadata that has Focuses on “preservation metadata, not metadata that has to be preserved”to be preserved”

Harvard:Harvard:

– Developed for Harvard’s Data Repository ServicesDeveloped for Harvard’s Data Repository Services

– Digital object placed in FTP “drop box”, along with Digital object placed in FTP “drop box”, along with instruction file in XML formatinstruction file in XML format

– Specifies XML Document Type Description for instruction Specifies XML Document Type Description for instruction file, including relevant metadata file, including relevant metadata

Points of ConvergencePoints of Convergence• Informed by OAIS reference model (implicitly or Informed by OAIS reference model (implicitly or

explicitly)explicitly)– Starting point for consensus on metadata frameworkStarting point for consensus on metadata framework– Identifies key aspects of preservation process metadata must Identifies key aspects of preservation process metadata must

supportsupport

• Primary objective of preservation metadata is to Primary objective of preservation metadata is to maintain accessibility of digital objects in face of maintain accessibility of digital objects in face of evolving technological environmentevolving technological environment

• Neutral on digital object type, and specifics of Neutral on digital object type, and specifics of preservation processpreservation process

IssuesIssues

• Scope of initiative:Scope of initiative: what is “preservation metadata”? what is “preservation metadata”?– metadata in a digital archival setting?metadata in a digital archival setting?

– metadata to support and facilitate preservation process?metadata to support and facilitate preservation process?

• Level of specificity:Level of specificity: how far can consensus extend? how far can consensus extend?– when do local imperatives outweigh benefits of consensus?when do local imperatives outweigh benefits of consensus?

• Level of descriptive granularity:Level of descriptive granularity:– collection, object, sub-object?collection, object, sub-object?

• Interoperability with existing metadata standardsInteroperability with existing metadata standards

• Implementation:Implementation:– syntax: XML, MARC, other?syntax: XML, MARC, other?

– embedded/encapsulated or separateembedded/encapsulated or separate

Future ActivityFuture Activity

• White paper:White paper:– revise draft to include working group feedbackrevise draft to include working group feedback– make final version publicly available (January 2001)make final version publicly available (January 2001)

• Working group:Working group:– develop comprehensive metadata frameworkdevelop comprehensive metadata framework– identify essential preservation metadata elements to identify essential preservation metadata elements to

support frameworksupport framework– identify and evaluate alternative implementation identify and evaluate alternative implementation

approachesapproaches– develop testbed/pilot applicationsdevelop testbed/pilot applications– recommendations for best practices/approachesrecommendations for best practices/approaches