associating RDF nodes with shapes

I took a close look at the node/shape association page, 
https://www.w3.org/2014/data-shapes/wiki/ISSUE-5:_Resource_Shape_Association

I would prefer an organization more like the following, as I think that it 
presents a clearer picture.


Where are Shapes/Constraints Validated

1/ A particular node

A shape/constraint may be validated only on a particular node in an RDF
graph.

In ShEx this would be done via a validation call that explicitly contains
the node and the shape.

In OWL constraints this would be done via an axiom of the form

<code>ex:node in constraint</code>

2/ Nodes that are instances of a class

A shape/constraint may be validated against all members of a class.  The
membership determination may be via explicit direct <code>rdf:type</code>
links, via class membership in some RDF-compatible semantics, or via some
intermediate process.

In SPIN this would be done via a <code>spin:constraint</code> link from the
class to a SPIN constraint.

In OWL constraints this would be done via an axiom of the form

<code>ex:Class <= constraint</code>

3/ Nodes that have a particular property value

A shape/constraint may be validated against nodes that have a particular
property value.

In OWL constraints this would be done via an axiom of the form

<code>some ex:property ex:value <= constraint</code>

4/ All nodes

A shape/constraint may be validated against all nodes (maybe only
non-literal nodes?).

In SPIN this would be done via a constraint on rdfs:Resource.

In OWL constraints this would be done via an axiom of the form

<code>owl:Thing <= constraint</code>

In ShEx this would be done by a validation call that explicitly mentions a
shape that all nodes are supposed to match.

5/ Triples with a particular predicate

A shape/constraint may be validated against all triples of a predicate.

In OWL constraints this would be done via

<code>ex:predicate <= constraint</code>

5/ Implicit

The form of a shape/constraint might determine how it is validated.

This is the general situation for OWL constraints.  An OWL constraint is
just an axiom that is supposed to be true.  Some kinds of OWL constraints
can be thought of being one of the types above, but other kinds of OWL
constraints have particular validation patterns.  For example, an OWL
constraint could require that a property is symmetric or transitive or that
the nodes that satisfy one constraint are precisely the same as those that
satisfy another, as in

<code>ex:Person and some ex:SSN = ex:USResident and age > 2</code>

Received on Tuesday, 16 December 2014 18:43:49 UTC