METS & PREMIS Cheat Sheet

METS (Metadata Encoding and Transmission Standard)

General Considerations

  • In this example, METS embeds PREMIS, meaning some metadata normally in PREMIS standalone files may be handled by METS.
  • Some expected elements may be missing from the LOC sample file.

Key Sections in METS

1. Metadata Wrapping vs. Referencing
  • <mets:mdWrap> – Metadata is embedded in the METS document (found in <mets:mdWrap MDTYPE="MODS"> for descriptive metadata and <mets:mdWrap MDTYPE="PREMIS"> for preservation metadata).
  • <mets:mdRef> – Not present in this file.
2. Header
  • <mets:metsHdr> which normally indicates the version of METS is missing in this file. I’m not sure why!
  • The attributes of <mets:mets> show us that the:
    • METS version used is ambiguous. I derived this example from the PREMIS XML Usage Examples page. The specific XML file that you used for this assignment is listed as using version 2.1 (I didn’t expect you to figure this out, but in case you were curious!)
    • PREMIS version used is 2.0 (xmlns:premis="info:lc/xmlns/premis-v2")
    • MODS version is 3.3 (xmlns:mods="http://www.loc.gov/mods/v3").
3. Descriptive Metadata (<mets:dmdSec>)
  • Uses MODS as the descriptive metadata standard (<mets:mdWrap MDTYPE="MODS">).
  • Title recorded in MODS: [Portrait of Louis Armstrong, between 1938 and 1948].
  • Photographer identified: William P. Gottlieb.
  • Subjects include Louis Armstrong, Jazz musicians, Trumpet players (1930-1950).
4. Administrative Metadata (<mets:amdSec>)
  • Technical Metadata (<mets:techMD>) – This is repeated twice for two objects, object1 and object2.
  • Digital Provenance (<mets:digiprovMD>) – This is repeated 7 times, describing different preservation events.
  • Source Metadata (<mets:sourceMD>) – Not present in this file.
  • Rights Metadata (<mets:rightsMD>) – Not explicitly included. Instead, we see <mets:mdWrap MDTYPE="PREMIS:AGENT">, which signals that elements inside <xmlData> should be interpreted using PREMIS rather than METS.
5. File Section (<mets:fileSec>)
  • Here we see a list of four files. Two are high-resolution TIFF files and another two are lower-resolution JPG files. Each uses <mets:FLocat> (File Location) to point to a URL.
6. Structural Map (<mets:structMap>)
  • <div> sections:
    • File pointers (<fptr>) – Links to files in <fileSec> (e.g., <mets:fptr FILEID="masterd1e102963"/>).
    • This section bundles together master with service copies (e.g. a masterd1e102963 with serviced1e1029631 and masterd1e102965 with serviced1e102965)
    • Structural Links (<mets:smLink>) are not present in this file.
    • Behavior Section (<mets:behavior>) is not present in this file.

PREMIS (Preservation Metadata: Implementation Strategies)

Note: Most PREMIS within this file does not declare a namespace (e.g. <premis: preceeding an element name. Instead, the PREMIS is “wrapped” using <mets:mdWrap MDTYPE="PREMIS:AGENT">: tags found within are interpreted as as PREMIS.)

Objects

  1. Intellectual Entity: PREMIS does not contain an element specific to Intellectual Entities. Instead, it will rely on the file invoking a descriptive metadata standard. The file uses <objectIdentifierValue>loc.music/gottlieb.09601</objectIdentifierValue> which points to a persistent handle. It also uses MODS to further describe the photograph/bibliographic entity.
  2. Representation: This refers to the full list of files representing the digital object, which covered by .
  3. File: Again, the lists each file.
  4. Bitstream: This is not present in the file.

Environment

  • There is an section, listing:
    • Software required: Adobe Acrobat (5.0), Windows XP.
    • Hardware details:
      • Processor: Intel x86 (60 MHz minimum).
      • Memory: 64 MB RAM (32 MB minimum).

Agents

  • The agent responsible for preservation is Library of Congress (Prints & Photographs Division) (<agentName>LC Repository</agentName>).

Events

  • Validation: File validated using Jhove 1.1e (<eventType>validation</eventType>).
  • Ingestion: File ingested into the repository (<eventType>ingestion</eventType>).
  • Migration: File migrated using Adobe Photoshop (<eventType>migration</eventType>).

Rights Statement

  • The file doesn’t explicitly have a Rights Statement. Instead, it links out to one using its <linkingRightsStatementIdentifierType> and <linkingRightsStatementIdentifierValue>.