METS: Metadata Encoding & Transmission Standard

Merrilee ProffittSociety of American ArchivistsAugust 2002

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Overview

Problem definitionMETS schema METS InitiativeSummary

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Overview

Problem definitionMETS schema METS InitiativeSummary

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Digital (Library) Objects

Digital Library Objects are… Reformatted to digital “Born digital” Simple Complex

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Structural metadata

Maps physical files (digital assets) to logical items (complex digital objects) Scanned print material A/V material Multimedia presentations

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Other Metadata

All types of digital objects have other (non-structural) metadata descriptive

• MARC, DC, MODS, etc. administrative

• rights technical

• format details Standards exist or emerging for these

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Overview

Problem definitionMETS schema METS InitiativeSummary

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METS Scope

Supports Structural metadata

• complex reformatted or born digital objects Metadata wrapper framework

• descriptive, administrative, structural, etc.• structural required• others use namespaces to reference

“extension schemas”

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METS Scope

Data transfer syntax between applications between institutions

Driver for applications page turner audio player multimedia presentation

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Ebind/MOA2

Electronic Binding Project (Ebind) 1996 modeled structural metadata

Making Of America II project Developed November 1997-January 2000 Funded by DLF and NEH, participants

• Cornell, NYPL, Penn State, Stanford, Berkeley

Designed for scanned archival collections XML DTD defining explicit descriptive,

administrative and structural metadata

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MOA2

February 2001 DLF workshop on structural metadata Harvard, LC, MOA2 participants, others

Outcome: METS definition emphasis on structural metadata,

archiving and sharing wider scope of participants, content

types change to namespace-qualified XML

schema, framework architecture

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METS Header

Administrativemetadata

FileInventory

Structuremap

Descriptivemetadata

Behavioralmetadata

METS metadata “buckets”

optional

optional

optional required

optional optional

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METS metadata

XML “extension schemas” descriptive metadata

• Dublin Core, MARC, MODS, etc. administrative/technical metadata

• NISO image technical metadata• LC schemas for A/V technical metadata• Rights metadata (XrML, ODRL)

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M e tad a ta R e fe re n ce M e tad a ta W rap p er

D e scrip tive M e ta d a ta

Metadata Reference (mdRef): A link to external descriptive metadata. The type of link (URN, handle, etc.) is included as an attribute, as is the metadata type.

Metadata Wrapper (mdWrap): Included descriptive metadata, as either binary data (Base64 encoded) or in XML using namespace mechanism. The metadata type is specified as an attribute.

Wrap or reference

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T e ch n ica lM eta da ta

IP R ig h tsM eta da ta

S o u rceM eta da ta

P re serva tionM eta da ta

A d m in is tra tiveM eta da ta

Technical Metadata (techMD): technical metadata regarding content files

IP Rights Metadata (rightsMD): rights metadata regarding content files or primary source material

Source Metadata (sourceMD): provenance information for content files.

Preservation Metadata (preservationMD): metadata to assist in preservation of digital content

All sections use generic metadata reference and wrapper subelements.

METS Administrative Metadata Section

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e tc ., e tc ., e tc.

F ile G ro up F ile

F ile G ro up F ile

F ile In ve n to ry(F ile G ro u p)

File Group (fileGrp): provides mechanism for hierarchically subdividing physical files, for example by type

File (file): provides a pointer to an external file or includes file content internally by Base64 encoding

METS File Inventory

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e tc ., e tc. e tc ....

D iv is io n M E T S P o in te r F ile P o in te r

D iv is io n M E T S P o in te r F ile P o in te r

D iv is io n

S tru c tu ra l M ap

The Structural Map provides a tree structure describing the original document. Each division (div) element is a node in that tree, and can identify content files associated with that division by a METS Pointer (mptr) or a File Pointer (fptr)

METS Structural Map

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METS and OAIS framework

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METS and OAIS framework

Submission Information Package (SIP)• METS as transfer syntax

Dissemination Information Package (DIP)

• METS as transfer syntax• METS as input to display applications

Archival Information Package (AIP)• METS stored internally in an archive

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Overview

Problem definitionMETS schema METS InitiativeSummary

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METS Initiative

Establishment of an editorial board with an editor-in-chief

Complete the first version of the schema, ensure support for other digital library work

Encourage field testing of METS and gather feedback

Tools Extension schemas

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Library of Congress

Network Development and MARC Standards Office provides hosting for developing the standard

WebsiteListserv

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Digital Library Federation/RLG

“Work coordinators”FundingAdministrative support

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Overview

Problem definitionMETS schema METS InitiativeSummary

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METS summary

Descriptive/technical/administrative metadata not defined internally points to external standard schemas

• Dublin Core, MARC, NISO imaging, etc. set of “best practice” schemas being

identified

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METS summary

Structural metadata defined internally and required SMIL-lite

• simple support for multimedia, audio/visual

• SMIL may replace eventually

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METS summary

Current users include• UC Berkeley (archival collections)• Harvard (scanned print publications, e-

journals)• Library of Congress (audio/visual collections)• EU MetaE project (historic newspapers)• Michigan State (oral history collections)• Univ of Virginia (FEDORA digital objects)• MIT (DSpace)• RLG (RLG Cultural Materials)• more daily...

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METS summary

Tools under development for metadata capture transformation transfer dissemination/display

Profiles necessary for interoperation Which extension schemas used? How structure maps are organized…

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METS summary

Current status version 1.0 (zeta) released in

February; version 1.0 released July editorial board established LC standards office for maintenance

agency RLG underwriting

• help with documentation and training, seek funding to host editorial board and to continue other efforts

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METS summary

METS is not all things to all people… Designed for local institutional application

support• Solving an immediate local problem• Common to many institutions• Flexible framework supports many institutional

situations Profiling necessary to interoperate

• For OAIS packages• For shared tools• For other kinds of interoperation (e.g. cross

repository search)

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For More Information…

METS homepage: http://www.loc.gov/standards/METS (includes information about the METS listserv)

Merrilee Proffitt, mgp@notes.rlg.org