Re: expanding work from quoted triples to graph terms

good afternoon;

> On 19. Oct 2023, at 18:56, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
> 
> The charter of this working group is very explicit its goal is to add quoted triples to RDF, and no other additions.  Renaming this new construct to triple terms is a reasonable change as all it does is change terminology and not implementation.  But my view is that expanding from quoted triples to quoted graphs or graph terms is a major expansion.  I'm not against this expansion but I believe that the working group should first do the work that it is chartered to do and only then explore something else.
> 
> So what else is needed to add triple terms to the RDF documents (ignoring the SPARQL documents for now)?   As far as I can tell the only technical work for the RDF documents that remains is semantics.   But semantics appears to be dependent of use cases.
> 
> So my suggestion is that the working group take a look at the use cases (and potentially submit new use cases) and determine which ones the working group will support.  Then a semantics that supports these use cases can be devised. Once this is done then the working group can look at graph terms if it so decides.
> 
> There is also SPARQL work to be done and this should also be prioritized over work on graph terms.


one may recall that, early in the discussions during the term of the community group, i expressed the concern that the project should be to provide a means to interpret existing rdf representation to support annotation, rather than to introduce additional elements into the abstract model.

this concern has remained over the years.
it is reinforced by the current reaction to the recent proposals to achieve the chartered goals by defining the appropriate way to interpret graphs.

while the effort required to achieve the chartered task is a valid concern, the working group should keep in mind that the proposal to interpret named graphs so as to provide for those features which are within the scope of the charter is not an expansion of scope.
it is just an alternative means to provide for that scope.
in particular, the requirement for a "graph term" is abstract, not concrete.

on one hand, neither the charter, nor the working group report, nor - more importantly, any of the use cases, restrict the scope to require implementation in form of a reified term data object
the scope neither excludes a mechanism which treats identifiers as designators for quoted triples, nor does it even require any expansion to include this mechanism.
so long as that mechanism satisfies section 2 of the community group report and supports the operators in its section 4.4, it is within the charter.
those are the only statements which might be viewed as precedential to this point in time.

if one suspends the syntax requirements for them moment - as is appropriate given the notational differences, the only pertinent conformance requirement delegates to a collection of "evaluation tests" (https://w3c.github.io/rdf-star/tests/sparql/eval/).
there is no discussion about representational requirements.

the only distinguishing passage in section 2 is

> RDF-star introduces quoted triple, which is a new kind of RDF term. A quoted triple is a triple used as the subject or object of another triple. Quoted triples can also be called "embedded triples".

there is nothing which governs its representation.
this leaves just definitions of its behaviour in section 4.4, which enumerates the operation to construct one, the operations which may be applied to one, and comparison predicates.
all of which can be defined based on named graphs and their content.


on the other hand, despite the group's efforts to date to elicit use cases which might indicate the necessity for reified statement terms, none has appeared.

further more, the current notation adopts a significant deficiency manifest in the property graph approach to annotation - the annotation target is ambiguous, and it introduces yet another - unless the sparql-star annotation is atomic, the content of the annotations themselves are ambiguous.

this means that the proposed approach to quoted tripes is itself deficient and the group should be open reconsider it.

the proposal based on graphs provides simple notational distinctions to avoid both of those problems and supports a mechanism which satisfies the charter's requirements as recorded in the released version of the community group report.

i suggest that the group devote adequate consideration to this direction as it has much to offer for the development of rdf.

best regards, from berlin
---
james anderson | james@dydra.com | https://dydra.com | datagraph gmbh

Received on Friday, 20 October 2023 13:37:43 UTC