preservation metadata: implementation strategies (premis)

Preservation Metadata: Implementation Strategies(PREMIS)

Rebecca GuentherLibrary of [email protected]

IS&T Archiving ConferenceApril 28, 2005

Apr. 28, 2005 IS&T Archiving Conference 2005

Preservation Metadata: Implementation Strategies

Overview of presentation

Background to PREMIS PREMIS membership and charge Preservation repositories implementation survey PREMIS Core elements group

• Development of data dictionary• Data model

Next steps Implementation issues



OCLC/RLG Preservation Metadata Framework Working Group

OCLC/RLG Preservation Metadata Working Group• Convened March 2000• Looked at CEDARS, NLA, NEDLIB, OCLC

Preservation metadata framework (June 2002)• Synthesized elements from existing sets• Based on OAIS information model• Elaboration of OAIS• Set of “prototype” preservation metadata elements

http://www.oclc.org/research/projects/pmwg/pm_framework.pdf



PREMIS

June 2003: OCLC/RLG sponsored new working group: PREMIS• Preservation Metadata: Implementation Strategies

Need• Practical and implementable, not broadly theoretical• Independent of specific implementation

Objectives• Define “core” set of preservation metadata elements, with

supporting data dictionary, applicable to broad range of digital preservation activities

• Identify and evaluate alternative strategies for encoding, storing, managing, and exchanging preservation metadata



Membership

Priscilla Caplan, FCLA (Chair) Rebecca Guenther, LC (Chair) Michael Alexander, British Library George Barnum, GPO Charles Blair, U. of Chicago Olaf Brandt, U. of Gottingen Adam Farquhar, British Library

David Gewirtz, Yale Kevin Glavash, MIT/Dspace Cathy Hartman, U. of N. Texas Helen Hodgart, British Library Nancy Hoebelheinrich, Stanford Roger Howard/Sally Hubbard,

Getty Museum Pam Kircher, OCLC John Kunze, Calif. Digital Library

Brian Lavoie, OCLC liaison Robin Dale, RLG liaison Vicky McCarger, LA Times Jerry McDonough, NYU/METS Evan Owens, JSTOR Erin Rhodes, NARA Madi Solomon, Walt Disney Co. Angela Spinazze, ATSPIN Gunter Waibel, RLG Lisa Weber, NARA Robin Wendler, Harvard Hilde van Wijngaarden, KB Andrew Wilson, NAA



Advisory Committee

Howard Besser, UCLA Liz Bishoff, OCLC (via

Colorado Digitization Program)

Gerard Clifton, National Library of Australia

Gail Hodge, CENDI Steve Knight, National Library

of New Zealand

Maggie Jones, Digital Preservation Coalition

Nancy McGovern, Cornell Cliff Morgan, Wiley UK Richard Rinehart, U. of

California, Berkeley



Implementation Survey Report

State of the art in Winter, 2003/2004 28 libraries, 7 archives, 3 museums, and 11 other 13 different countries; 45% from U.S. 38% in planning; 33% development; 46% production



Survey findings

Little experience with digital preservation• Most didn’t have active preservation strategy• Many not yet in production• Cannot assess adequacy of metadata

Lack of common vocabulary and conceptual framework• Informed by OAIS reference model• Difference of opinion as to meaning of OAIS compliance

Metadata• Many recording rights, provenance, technical,

administrative, descriptive and structural Most repositories serve goals of both preservation and

access



Trends

Store metadata redundantly in XML or relational database and with content data objects

Use METS for structural metadata and as container for descriptive and administrative; MIX for images

Use OAIS as framework and starting point Maintain multiple versions (originals, some normalized or

migrated) in repository with complete metadata for all versions

Choose multiple strategies for digital preservation



Core Elements

Mission: Define a core set of implementable preservation metadata elements.



Core Elements


• Information that supports and documents the digital preservation process;

• Information that supports the viability, renderability, understandability, identity and authenticity of digital objects over time.



Core Elements


• What most working preservation repositories are likely to need to know

• Core does not imply mandatory



Core Elements


• As rigorous as possible• As much explanation as possible• Implementation neutral -- “This is what you

have to know”• Values can be automatically supplied and

processed -- no lengthy textual descriptions



Core Elements: Data Model

Intellectual Entities

Rights

Objects

Agents

Events



Scope of data dictionary

Implementation independent Descriptive metadata out of scope Metadata about Agents is limited Technical metadata applying to all or most format types Media or hardware details is limited Business rules are essential for working repositories, but

not covered Rights information for preservation actions, not access



Sample data dictionary entrySemantic unit size Semantic components

None

Definition The size in bytes of the file or bitstream stored in the repository.

Rationale Size is useful for ensuring the correct number of bytes from storage have been retrieved and that an application has enough room to move or process files. It might also be used when billing for storage.

Data constraint Integer Object category Representation File Bitstream Applicability Not applicable Applicable Applicable Examples 2038927 Repeatability Not repeatable Not repeatable Obligation Optional Optional Creation/ Maintenance notes

Automatically obtained by the repository.

Usage notes Defining this semantic unit as size in bytes makes it unnecessary to record a unit of measurement. However, for the purpose of data exchange the unit of measurement should be stated or understood by both partners.



Semantic units pertaining to objects

objectIdentifier preservationLevel objectCategory objectCharacteristics creatingApplication originalName Storage environment

signatureInformation relationship linkingEventIdentifier linkingIntellectual

Entity Identifier linkingPermission

StatementIdentifier



objectCharacteristics

compositionlevel fixity size format significantProperties inhibitors



Semantic units pertaining to Events

eventIdentifier eventType eventDateTime eventDetail eventOutcome eventOutcomeDetail linkingAgentIdentifier linkingObjectIdentifier



Semantic units pertaining to Agents

agentIdentifier agentName agentType



Semantic units pertaining to Rights

permissionStatement permissionStatementIdentifier relatedObject grantingAgent grantingAgreement permissionGranted

act restriction termOfGrant permissionNote



Next steps

PREMIS deliverables (May 2005)• Data dictionary and report• XML schemas• Draft for experimentation to remain stable for a year• Revisions will be based on results of testing

Follow-up activities• Testbeds for implementation and exchange• Community outreach• Establish maintenance activity• Consider formal standardization



Implementation considerations

Schema use with specific implementations (e.g. METS) Machine generation of metadata Tools Role of registries (format, environment) Prospects for collaboration and exchanging information

content Rights and permissions Emergence of best practices Support needed from PREMIS maintenance activity



For More Information:

PREMIS Web Site• www.oclc.org/research/projects/pmwg

“Implementing Metadata in Digital Preservation Systems: The PREMIS Activity” D-Lib (April ‘04)• www.dlib.org/dlib/april04/lavoie/04lavoie.html

RLG DigiNews October 2004 and December 2004 issues• www.rlg.org/en/page.php?Page_ID=12081

Priscilla Caplan: [email protected]

Rebecca Guenther: [email protected]

preservation metadata: implementation strategies (premis)

Documents

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