What URL should I use for unknown Actors?

Priority 2, Best Practice Established

Problem Statement

A common practice in museum collections management is to create parties within the CMS that represent unknown people. Sometimes these parties have additional information about them (for example, "Unknown African"), but often they are just "Unknown".

This practice does not cause any problems within the collection management system, but in Linked Open Data a naive mapping of the "Unknown" party implies that all works created by "Unknown" were created by the same individual, which is likely incorrect.

What pattern do we use in our mappings to distinguish between unknown actors?

Best Practice:

AAC Best Practice is to create unique URLS for all unidentified agents identified within a Object record (or any other record). We recommend using the object ID and the agent's role to determine a unique ID. We recommend NOT using "unidentified" within the URL, to avoid consusion in the case the entity is later identified.

Additionally, this entity should be assigned a type that indicates that they are an "unknown" entity to assist with recall.

If at a later date this agent becomes identified, the previously used URL should remain valid—either it should be redirected in some way to the new ID (if it exists), or statements about the now identified entity should be associated with the previous ID, but not both.

Discussion:

There is a long discussion of this in Github Issue NPG #50.

Reference:

Linked Open Data FAQs

Defining Types

How do I specify types for entities?
Priority 1
✔ Best Practice Established
How do I specify types for predicates?
Priority 1
✔ Best Practice Established
What existing extensions to the CIDOC-CRM should I use?
Priority 2
✔ Best Practice Established

Defining URL Structures

What URL should I use for unknown Actors?
Priority 2
✔ Best Practice Established
What is the root URL for each AAC Partner?
Priority 2
✔ Best Practice Established
What is returned when a URL is dereferenced?
Priority 3
✔ Best Practice Established
Which ID is most appropriate for URL construction?
Priority 3
✔ Best Practice Established

Labeling

What are best practices for modeling text strings?
Priority 2
✔ Best Practice Established
What is best practice for labeling external authorities?
Priority 3
✔ Best Practice Established
How do I handle strings in languages other than english?
Priority 4
✔ Best Practice Established

Modeling

How do I handle complexity in knowledge representation?
Priority 1
✔ Best Practice Established
How do I model lists of entities or multiple values?
Priority 2
✔ Best Practice Established
How should I model parts of Actor names?
Priority 2
✔ Best Practice Established

Reconciliation

How do I reconcile objects to authorities?
Priority 2
✔ Best Practice Established
Which entity should I link to in an authority file?
Priority 2
✔ Best Practice Established

Triplestores, RDF, and Inferencing

Which namespace should I use for the CIDOC CRM as LOD?
Priority 1
✔ Best Practice Established
How do I create an RDF representation of an entity?
Priority 3
✔ Best Practice Established
Where should AAC-created vocabularies be hosted?
Priority 3
✔ Best Practice Established
What serialization of RDF should I publish?
Priority 4
✔ Best Practice Established