Proposal to change the Constraint specification in the Ontology

Dear POE WG members,

 

the ODRL Information Model specifies for a Constraint three mandatory
properties to define a constraint expression: leftOperand rightOperand (or
rightOperandReference) and operator. These three properties cannot be
retrieved from a current ODRL ontology instance: the operand is available,
but the current design takes the RDF triple object of an assertion of the
left operand and makes it the predicate of an assertion where the object is
the same as in an assertion of the right operand. Simply said it mixes the
assertions of the left and the right operand and makes it almost impossible
to find out what the operands and their objects (values) are. This design is
based on a note of the specification of the rightOperand and not on basic
ontology rules.

 

Therefore Victor and Michael propose to modify the ODRL ontology to make it
fully compliant to the Information Model:

-          Create a leftOperand property of the Constraint class and set as
rdfs:domain the LeftOperand class

-          Define a LeftOperand class …

-          … and make all “names of a constraint”/left operand values like
count, dateTime etc an instance of the LeftOperand class

-          Remove the special note about the old mixed
rightOperand/leftOperand design from the rightOperand specification

-          Adjust the wording of some free-text specifications

The file ODRL22.ttl showing these changes can be found in the issue84 branch
of the POE Github repository -
<https://raw.githubusercontent.com/w3c/poe/issue84/vocab/ODRL22.ttl>
https://raw.githubusercontent.com/w3c/poe/issue84/vocab/ODRL22.ttl 

 

As this is a fundamental change of the Constraint class of the ontology it
needs approval by the Working Group.

Please go over this file and have a look at issue 84 at
<https://github.com/w3c/poe/issues/84> https://github.com/w3c/poe/issues/84

A decision should be taken at an upcoming POE call.

 

Thanks,

Michael & Victor

 

Michael Steidl

(IPTC)

 
Víctor Rodríguez-Doncel
D3205 - Ontology Engineering Group (OEG)
Departamento de Inteligencia Artificial
ETS de Ingenieros Informáticos
Universidad Politécnica de Madrid