[oslc-core] Ambiguity in Resource Shape definition + consequent questions

[John Arwe]

[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
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