John, At our last telecon I took the action of suggesting clarifications for the spec text [1].
The current decription for oslc:describes is: Type or types of resource described by this shape. I suggest this description: This shape describes resources that are of any of these types. That is, the shape applies to resources that are in the union of the types. Note that if a resource has multiple rdf:type properties then the resource is in the intersection of those types. Therefore a shape S applies to a resource R if R has a type T and there is a triple S oslc:describes T. Regards, ___________________________________________________________________________ Arthur Ryman DE, PPM & Reporting Chief Architect IBM Software, Rational Toronto Lab | +1-905-413-3077 (office) | +1-416-939-5063 (mobile) From: John Arwe <[email protected]> To: [email protected] Date: 01/11/2012 11:19 AM Subject: [oslc-core] Ambiguity in Resource Shape definition + consequent questions Sent by: [email protected] [1] Defines the Resource Shape resource definition. It includes the following property definition: > oslc:describes zero-or-many True Resource Reference n/a Type or types of resource described by this shape. Q1: This allows for multiple oslc:describes triples in a resource shape, but leaves open what the relationship is between these values and the (possibly multiple) rdf:type values in any given "described" resource instance (i.e. what condition(s) must be true in order for a given shape to describe a given resource instance appears to be under-specified). Breaking it down case by case, and stating what I *think* is the intent for each (looking for confirmation/disputes of this interpretation) with ??? in cases where [1] really leaves me guessing. I have implementation folks already interpreting the ??? cases differently, BTW. Q1a; RS oslc:describes = { Fred } resource instance RI rdf:type = { Fred } intent: RS describes RI other cases where both {}s have single values: RS does not describe RI Q1b; RS oslc:describes = { Fred, Wilma , Barney } resource instance RI rdf:type = { Fred } (or { Wilma } or { Barney } , but only 1 in an instance) intent ???: RS describes RI ??? other cases where RI {}s has a single values: RS does not describe RI (one alternative interpretation was that the type sets must be identical in order to say the RS describes the RI) Q1c; RS oslc:describes = { Fred, Wilma , Barney } resource instance RI rdf:type = { Fred , Bambam } intent ???: RS describes RI ??? other cases where both {}s have multiple values: RS describes RI iff at least one type URI is present in both sets (i.e. the intersection of types is non-empty) Q2: (editorial change I think) from: A Resource Shape describes the properties that are allowed or required by one type of resource. to: A Resource Shape describes the properties that are allowed or required by one or more types of resource. Q3: Is oslc:describes cardinality of 0:n (specifically the lower bound) intended? vs 1:n? If 0 is the intent, would need to tweak Q2 Q4: Another disagreement between the words and oslc:describes cardinality from: providing a machine-readable definition of an OSLC resource type . to: providing a machine-readable definition of one or more OSLC resource types. FWIW: I kept "resource type" there, but "resource definition" might be more in keeping with the rest of the specs' content... did not do a wide search. Q5: (editorial nit?) from: OSLC Creation Factory MAY provide a Resource Shape ... create a resource to: OSLC Creation Factory MAY provide Resource Shapes ... create resources ...and similiar one for Query Capability in the next sentence. Q6: (editorial nit?) from: A Resource Shape resource can have a title and a type . to: A Resource Shape resource can have a title and a set of types. ("one or more" again would do equally well) [1] http://open-services.net/bin/view/Main/OSLCCoreSpecAppendixA?sortcol=table;table=up;up=#oslc_ResourceShape_Resource Best Regards, John Voice US 845-435-9470 BluePages Tivoli OSLC Lead - Show me the Scenario _______________________________________________ Oslc-Core mailing list [email protected] http://open-services.net/mailman/listinfo/oslc-core_open-services.net
