the premis working group: preservation metadata for digital repositories

The PREMIS Working Group:Preservation Metadatafor Digital Repositories

DLF Fall ForumOctober 26, 2004 Rebecca GuentherLC/NDMSO [email protected]

Oct. 26, 2004 DLF-PREMIS 2

Preservation Metadata Functions

• Information that supports and documents the digital preservation process:• Establish provenance: track chain of custody and

alterations over time• Details authenticity• Documents technical processes object has

undergone• Describes technical details of object• Describes the environment from which it

originated• Specify rights management information


Preservation Metadata Functions (cont.)

• Provide information to maintain resources over the long term:• viability: object’s bitstream is intact• renderability: object can be translated

to a form that can be viewed or used• understandability: rendered content can

be interpreted and understood


Background• March 2000: OCLC and RLG jointly sponsor international

working group on preservation metadata• Identify key issues/challenges• Seek consensus on recommendations and best practice

• White paper (January 2001)• Defined preservation metadata; role in preservation process• Reviewed/synthesized existing preservation metadata schemes

• Preservation metadata framework (June 2002)• Comprehensive description of types of information constituting

preservation metadata• Based on OAIS information model• Set of “prototype” preservation metadata elements


Aftermath …

• Framework …• Consolidated expertise• Provided foundation for developing formal

preservation metadata specifications• Common departure point for different

schema implementations

• But ... further scope for collaboration in preservation metadata• Needed best practices/recommendations for

implementing preservation metadata in real world digital archiving systems


Issues unresolved in WG

• How minimal is a core preservation metadata element set?

• How much metadata can be generated automatically?

• Is it useful to apply metadata elements by object type or object behavior?

• Levels of granularity not addressed• Need to provide less abstract view of

preservation metadata for implementation


PREMIS

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

• 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• Stefan Strathmann, U. of

Gottingen• 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


PREMIS Subgroups

• Core elements• Establish core metadata elements and data dictionary• Developed a data model• Has had 2 face-to-face meetings• Weekly conference calls

• Implementation• Examine alternative strategies for encoding, storage

and management of preservation metadata• Conducted a survey of practices• Monthly conference call

• Expect to complete activities by end of 2004


Core elements subgroup

• Development of data model• Objects• Events• Agents• Intellectual entities• Rights

• Data dictionary structured according to entities


Core Elements

• Conducting element-by-element review of prototype elements from metadata framework• Is the element “core”?• How is it being used at WG members’

institutions?• How should it be implemented/populated?• Elements not covered by the framework?


Objects

• Identifiers• Location• Descriptive metadata out of scope• Technical metadata not specific to

particular file format• Levels of objects: representation, file,

filestream, bitstream


Objects:Technical metadata

• Object characteristics • Fixity• Size• Format (including link to format registry)• Inhibitors• Significant properties• Creating application information

• Environment (software, hardware)• Externally defined technical metadata (e.g.

Z39.87/MIX)


Events

• Digital provenance/process information• Actions that involve one or more objects• May be related to one or more agents• Semantic units

• Event identifier• Event type• Event outcome• Event detail• Event date/time


Agents

• Agent descriptions out of scope• Attributes of agents associated with

preservation events and rights management• May carry-out, authorize, or compel one or more

events • may create or act upon one or more objects• may hold or grant one or more rights

• Semantic units• Agent identifier• Agent name


Rights and relationships

• Rights• Only in context of right to preserve• Collecting rights use cases

• Relationships• Data model expresses relationships

between entities• Relationships between objects

• Derivative, dependency, structural


Implementation Strategies subgroup

• Conducted survey of preservation repositories to explore the state of the art

• Questions about policies, governance, funding, system architecture, preservation strategies, metadata implementation

• 70 surveys sent• Responses from 28 libraries, 7 archives, 14

other in 13 different countries• 10 national libraries, 6 national archives• Survey published Oct. 2004


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


Survey findings (cont.)

• Metadata• Many recording rights, provenance, technical,

administrative, descriptive and structural

• Consistent roles in preservation scope and policies (academic libraries, archives, national libraries)

• Substantial use of METS, Z39.87/MIX, OCLC sets

• 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


Looking ahead

• Finalize core preservation metadata elements set

• Complete data dictionary

• XML schemas to support exchange of core elements for digital provenance/process and technical metadata

• Final PREMIS report by end of 2004

• Community outreach: opportunities for public comment

• Follow-on activities?


More information…

• PREMIS Web site:http://www.oclc.org/research/projects/pmwg/

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

• Rebecca Guenther: [email protected]

• Priscilla Caplan: [email protected]

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

http://www.dlib.org/dlib/april04/lavoie/04lavoie.html