METS

This article is about the metadata encoding standard. For the major league baseball team, see New York Mets. For other uses, see Mets (disambiguation).

The Metadata Encoding and Transmission Standard (METS) is a metadata 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.

Introduction

METS is an XML Schema designed for the purpose of:

• Creating XML document instances that express the hierarchical structure of digital library objects.
• Recording the names and locations of the files that comprise those objects.
• Recording 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 libraries

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.

• Where 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.
• However in a digital library it is possible to create e-book like PDF file, Tiff file which can be seen a single physical book and reflect the integrity of the original.

Characteristics of METS documents

Any METS document has the following features:

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

• 

  Sections of a METS document

The 7 sections of a METS document

• METS header metsHdr: Contains metadata describing the METS document itself, such as its creator, editor, etc.
• Descriptive Metadata dmdSec: May contain internally embedded metadata or point to metadata external to the METS document. Multiple instances of both internal and external descriptive metadata may be included.
• Administrative Metadata amdSec: Provides information regarding how 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 files comprising the digital library object (such as master/derivative relationships, migrations, and transformations). As with descriptive metadata, administrative metadata may be internally encoded or external to the METS document.
• File Section fileSec: Lists all files containing content which comprise the electronic versions of the digital object. file elements may be grouped within fileGrp elements to subdivide files by object version.
• Structural Map structMap: Outlines a hierarchical structure for the digital library object, and links the elements of that structure to associated content files and metadata.
• Structural Links structLink: Allows METS creators to record the existence of hyperlinks between nodes in the Structural Map. This is of particular value in using METS to archive Websites.
• Behavioral behaviorSec: Used to associate executable behaviors with content in the METS object. Each behavior has a mechanism element identifying a module of executable code that implements behaviors defined abstractly by its interface definition.

METS profiles

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 use

• 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 also

• Digital Item Declaration Language
• Dublin Core, an ISO metadata standard
• Preservation Metadata: Implementation Strategies (PREMIS)
• Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH)
• BagIt
• OAI-ORE

External links

• Network Development and MARC Standards Office
• Library of Congress
• Digital Library Federation
• METS Official web site