PREMIS: keeping a digital artwork usable

Status: working Museum application profile; the cited standard remains authoritative

The question

What must the Museum preserve so this work can still be studied and experienced?

A digital artwork may depend on source code, a token hash, libraries, fonts, network services, a browser, a display, timing, and the actions of a viewer. A screenshot preserves one appearance. It does not preserve the system that made the appearance possible.

PREMIS gives the Museum a disciplined way to name the things under its care, the events that affect them, the people and software involved, and the permissions that govern preservation work. It is the conservation record for digital material.

In the Casey Reas accession

For Casey Reas's CENTURY #31, the Museum has a checksum for the retained metadata bytes. That checksum tests whether those exact bytes have changed. The record can also identify the artwork, its external token, an observed generator, the p5.js environment, and documentation stills. Those are different preservation objects.

The live generator rendered when it was examined. A complete, self-contained generator and dependency package has not yet been retained. PREMIS lets the Museum say precisely what has been captured and why preservation remains in progress.

What PREMIS contributes

PREMIS 3.0 organizes preservation information around four entities:

The Object hierarchy is equally important:

• an Intellectual Entity is the coherent intellectual or artistic work, or a described environment;
• a Representation is the complete set of files and structural information needed for a reasonable rendition;
• a File is a named, ordered sequence of bytes;
• a Bitstream is meaningful data within a file.

The Museum reserves Representation for a set that can actually support the declared rendition. A remote URL, thumbnail, or screenshot cannot receive that designation by convenience.

Museum application profile

Objects and their roles

The Museum assigns every preservation Object a stable identifier and a role. Roles include source capture, metadata response, generator source, dependency, environment description, display derivative, documentation surrogate, accessibility rendition, evidence package, and repository inventory.

An external CAIP-19 asset identifier remains separate from the Museum Object identifier. One names the chain asset; the other maintains institutional continuity through preservation versions and future migrations.

Fixity with a declared scope

A digest always names its algorithm and the exact bytes covered. The record also stores byte size, media type, acquisition method, source, event, and validation outcome. A digest of an HTTP response body and a digest reported by an upstream API are different assertions even when their values happen to match.

Significant properties and environments

The profile records the characteristics whose loss would materially change the work or the evidence available to study it. For a generative work these may include dimensions, timing, interaction, state transitions, color behavior, randomness, token input, and dependencies.

Software and hardware environments are preservation Objects too. Browser, library, operating-system, font, graphics, input, and network dependencies are recorded at the level supported by evidence. A successful render is an Event with conditions and outcome, rather than a permanent claim of compatibility.

Events and outcomes

Every preservation Event records:

event identifier and type
event date and time
Objects used, affected, or generated
Agents and their roles
method and tool versions
outcome and outcome details
evidence references
source Museum release

Corrections and later tests create new Events. They do not erase the earlier observation.

What this standard leaves to the Museum

PREMIS records preservation evidence and repository actions. It does not authenticate an issuer, decide accession, establish legal title, prove an artist's intent, or make an incomplete capture complete. A successful event outcome is the repository's recorded result and remains traceable to its evidence.

For machines and implementers

Authority and version

• Authority: PREMIS Editorial Committee; official publication hosted by the Library of Congress.
• Data Dictionary: PREMIS 3.0, published June 2015 and revised November 2015; the Library of Congress identifies it as the current version.
• XML Schema: PREMIS 3.0.
• OWL ontology: PREMIS 3.0.0. It complements the Data Dictionary and imports PROV-O.
• Data Dictionary: PREMIS 3.0.
• XML Schema: premis-v3-0.xsd.
• RDF namespace: http://www.loc.gov/premis/rdf/v3/.

Licensing is artifact-specific. The PREMIS OWL usage guidelines state CC BY 4.0, and the PREMIS-EC ontology repository states CC0 1.0 for its repository content. Those statements do not automatically apply to every Library of Congress PREMIS publication.

Museum serialization target

The source Museum record remains authoritative. The planned preservation projection provides:

1. PREMIS 3.0 XML for repository exchange;
2. PREMIS OWL with PROV-O relations for graph use;
3. a closed Museum JSON profile for routine validation and web delivery.

Each export includes the Museum profile version, PREMIS version, source commit and manifest commitment, generator version, generation time, digest, and validation result.

Required Museum object shape

{
  "object_id": "6529NM.2026.001.01",
  "object_category": "intellectual_entity",
  "external_asset_id": "eip155:1/erc721:0xa7d8d9ef8d8ce8992df33d8b8cf4aebabd5bd270/100000031",
  "preservation_status": "in_progress",
  "representations": [],
  "files": [
    {
      "role": "metadata_response",
      "fixity": {
        "algorithm": "sha256",
        "value": "e193e1436718786aac6e96aac69d70b3ecbb224576626378137683bbf6916e74",
        "scope": "retained HTTP response body bytes"
      }
    }
  ]
}

An empty representations array is intentional here. The present record does not claim that the complete set needed for an autonomous rendition has been preserved.

Validation and conformance

Validation combines PREMIS 3.0 XSD checks, RDF parsing where applicable, controlled-vocabulary checks, closed Museum JSON Schema, SHACL shapes, stable identifier checks, fixity verification, and evidence-link resolution.

The Museum's first formal target is a documented Level 1B mapping: mandatory Object elements for each supported Object category, one or more Agents, and sufficient Event metadata to document preservation actions taken by the repository. Level 2B additionally requires established routine export processes and demonstrated Object, Agent, and Event export. PREMIS Rights remain in the Museum profile even though the formal conformance levels do not include them.

The Casey Reas accession

Museum state: source_fields_present. The canonical accession contains stable Objects, retained metadata bytes and fixity, technical observations, environment facts, Agents, Events, and preservation permissions sufficient for a substantial PREMIS mapping. It does not yet contain a validated PREMIS 3.0 export or a complete autonomous generator Representation. Preservation status remains in_progress for all seven works.

Official sources

• Library of Congress, PREMIS official home.
• Library of Congress, PREMIS version 3.
• PREMIS Editorial Committee, PREMIS OWL documentation.
• PREMIS Editorial Committee, PREMIS OWL usage guidelines.
• PREMIS Editorial Committee, conformance statement.