What existing extensions to the CIDOC-CRM should I use?

Priority 2, Best Practice Established

Problem Statement:

Previous projects have developed CIDOC-CRM mappings of museum data, including the British Museum, SAAM, and YCBA. To complete these mappings, many of the institutions have defined custom concepts, classes, and properties that extend the CIDOC-CRM. Should the AAC use any of these extensions? If so, which ones?

Additionally, the CRM has published a series of extensions, including the CRMpc and CRMinf. Are any of these useful?

Best Practice:

Our current practice is to use the CRM when possible, and to choose from extensions as needed to fill gaps. In particular, we are using the CRMpc extension to allow for CRM N.1 properties and the http://www.qudt.org ontology for computable dimensions.

In general, we prefer existing, widely used extensions over creating new ones.

Discussion:

(From Rob)

We should look to broadly adopted ontologies first, and then any community extensions. So if we need a term from BM/YCBA, we should use it.

(From Vladimir)

Don't look at http://crm.rkbexplorer.com/. It "polluted CRM" by adding 2x more custom properties such as PX.watch_pendant_made_in. Instead, the next mapping we did, added a few custom properties, and uses a lot more of CIDOC CRM and generic mechanisms for extension.

Search for "revealed" at http://vladimiralexiev.github.io/pubs/.

E.g. the above would be modeled like this (rdf:type skipped for brevity):

<object/123> p2_has_type <watch>; 
    P42_is_composed_of  <object/123/pendant>.
<object/123/pendant> p2_has_type <pendant>;
    P108i_was_produced_by <object/123/pendant/production>.
<object/123/pendant/production> P7_took_place_at <place>.

(From conference call, 9/28/2016)

  • How frequent or infrequent will this issue be?

    • Within a couple months, as we build browse app, we will identify whether the CRM allows for sufficient specificity, or we need something additional beyond CRM
    • Possible issues like distinguishing between first/middle names or the artist vs painting of the artist
    • We will see examples over the next couple months and can make decisions from that
  • RS: Concern that we conform to the CRM but not to what the rest of the world does for common data entities (like names)

    • DN: Back to the knowledge representation vs usability discussion
    • CK: This ship has sailed, there is a lot of legacy modeling, so making a big change would delay things even further
    • EF: Doubts about CRM is growing — “hinders progress” — so tempted to go with Getty approach, but it may not be able to afford this within this project at this time
    • CK: Building to the model that DN has been establishing would have been a better start, but coming a little late
    • Good news — the differences will be much fewer than the areas where AAC agrees with Getty and also things like ArtTracks and others

DECISION:

  • Continue on as we are, review when we have sufficient examples
  • Don’t publish the current modeling in these areas as “Good Practices” but make sure they are described as “Lessons Learned"

(From Vladimir 12/13/2016)

For Getty CONA mapping I've defined some simple extensions like crmx:preferred, crmx:sort_order, crmx:property (the missing piece of crm:E13_Attribute_Assignment). See CRMX at Getty (Rob has access). There are a few more to cover CCO, eg crmx:P2_extent "art of object or work contributed by an agent, measured in a dimension, or described by a subject"

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