20111019

• select CRM naming variant
  • cidoc-ids.txt (CIDOC RDFS)

    crm:E1.CRM_Entity, crm:P1F.is_identified_by, crm:P1B.identifies

    By the official CIDOC group. This is what we currently use.

  • ecrm-ids.txt (Erlangen OWL)

    crm:E1_CRM_Entity, crm:P1_is_identified_by, crm:P1i_identifies

  • owl2-ids.txt (BloodyBytes OWL2)

    crm:E1_CRM_Entity, crm:P1_is_identified_by

    Has NO INVERSE properties!

Naming in Turtle and Sparql

• "." and "/" are not valid nameChar in Turtle (and neither . The valid ascii chars are [0-9A-Za-z_-], according to the spec and this validatator
• So we cannot use stuff like:

  crm:P1F.is_identified_by (because of the dot)
  rkd:frame/material/wood/gold_plated (because of the slashes)

• Mariana: Absolute URIs are to be used in the problematic cases quoted above.
• Vlado: prefixes are an essential aid for understanding, so we cannot give them up so easily.
  While we could give them up for Turtle (which is just an input format), I don't think we can afford to give them up for Sparql (which means writing kilometric queries that nobody can understand).

@base

Barry, you're a turtle expert, can you help? Are there less-anal Turtle processors we can use?
Barry Norton: You have more flexibility (but only one at a time) with the document base URI, e.g.:

But this means changing it within the document.
Vlado: and IMHO is a sure way to insanity

Longer prefix

The best alternative seems to be to have the whole (reflecting the hierarchy) set of prefixes, and to include the dots in these, e.g.:

Vlado: neat trick! But this creates around 250 prefixes... I'd rather select a CRM naming variant that is Turtle-friendly

Naming of thesaurus values

The original idea was to use value URIs having as prefix:

• the thesaurus scheme (type) URI: for values without parent (skos:broader)
• the parent value: for values with parent

Eg:

What to do for hierarchical values (eg wood/gold_plated)?
This makes the prefixes too many and too long:

So it's better to replace the last / with eg --:

Mariana: A solution was found that < > escape the . and the / in the uri, and allows to use namespace shortcuts instead of absolute URIs.

Modeling Questions

• which CRM schema defines the Inverse properties?
• document Subproperty policy
  If you use has_note and a sub-property has_name, you gain nothing in specificity
  then has_note cannot be used for querying, since it will also return the has_name. Therefore all notes should use a subtype
• document Subproperty naming
  Best us to use the number from CRM and change the prefix and name:

  rso:P3.has_comment rdfs:subPropertyOf crm:P3.has_note

Visio tasks

• image_objects_carriers@crmg: P65 to Image instead of P62; P138 or P67 to subject