For the baseball team, see New York Mets.
For the measure of exercise intensity, see metabolic equivalent.

The Metadata Encoding and Transmission Standard schema is a standard for encoding descriptive, administrative, and structural metadata regarding objects within a digital library, expressed using the XML schema language of the World Wide Web Consortium. The standard is maintained in the Network Development and MARC Standards Office of the Library of Congress, and is being developed as an initiative of the Digital Library Federation.


METS is an XML Schema designed for the purpose of:

  • Creating XML document instances that express the hierarchical structure of digital library objects.
  • Mention the names and locations of the files that comprise those objects.
  • Mention the associated metadata . METS can, therefore, be used as a tool for modeling real world objects, such as particular document types.

Depending on its use, a METS document could be used in the role of Submission Information Package (SIP), Archival Information Package (AIP), or Dissemination Information Package (DIP) within the Open Archival Information System (OAIS) Reference Model.

Digital libraries Vs Traditional librariesEdit

Maintaining a library of digital objects requires maintaining metadata about those objects. The metadata necessary for successful management and use of digital objects is both more extensive than and different from the metadata used for managing collections of printed works and other physical materials.

  • A traditional library may record descriptive metadata regarding a book in its collection, the book will not dissolve into a series of unconnected pages if the library fails to record structural metadata regarding the book's organization, nor will scholars be unable to evaluate the book's worth if the library fails to note that the book was produced using a Ryobi offset press.
  • The same cannot be said for a digital library. Without structural metadata, the page image or text files comprising the digital work are of little use, and without technical metadata regarding the digitization process, scholars may be unsure of how accurate a reflection of the original the digital version provides.

Characteristics of METS documentsEdit

Next features can be attributed to any METS document:

  • An open standard (non-proprietary)
  • Developed by the library community
  • Relatively simple
  • Extensible
  • Modular

The 7 sections of a METS documentEdit

  • METS header: It contains metadata describing the METS document itself, including such information as creator, editor, etc.
  • Descriptive Metadata: This section may point to descriptive metadata external to the METS document or contain internally embedded descriptive metadata, or both. Multiple instances of both external and internal descriptive metadata may be included in the descriptive metadata section.
  • Administrative Metadata: This section provides information regarding how the files were created and stored, intellectual property rights, metadata regarding the original source object from which the digital library object derives, and information regarding the provenance of the files comprising the digital library object (i.e., master/derivative file relationships, and migration/transformation information). As with descriptive metadata, administrative metadata may be either external to the METS document, or encoded internally.
  • File Section: The file section lists all files containing content which comprise the electronic versions of the digital object. <file> elements may be grouped within <fileGrp> elements, to provide for subdividing the files by object version.
  • Structural Map: This section is the heart of a METS document. It outlines a hierarchical structure for the digital library object, and links the elements of that structure to content files and metadata that pertain to each element.
  • Structural Links: This section allows METS creators to record the existence of hyperlinks between nodes in the hierarchy outlined in the Structural Map. This is of particular value in using METS to archive Websites.
  • Behavioral: A behavior section can be used to associate executable behaviors with content in the METS object. Each behavior also has a mechanism element which identifies a module of executable code that implements and runs the behaviors defined abstractly by the interface definition.

METS profilesEdit

METS Profiles are intended to describe a class of METS documents in sufficient detail to provide both document authors and programmers the guidance they require to create and process METS documents conforming with a particular profile.

A profile is expressed as an XML document. There is a schema for this purpose. The profile expresses the requirements that a METS document must satisfy. A sufficiently explicit METS Profile may be considered a data standard.

METS Profiles in useEdit

  • Musical Score (may be a score, score and parts, or a set of parts only)
  • Print Material (books, pamphlets, etc)
  • Music Manuscript (score or sketches)
  • Recorded Event (audio or video)
  • PDF Document
  • Bibliographic Record
  • Photograph
  • Compact Disc
  • Collection

See alsoEdit

External linksEdit

de:Metadata_Encoding_&_Transmission_Standard fr:METS zh:METS

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