victory is not declared, but won

Dear WG,


regarding Agenda 2. - Proposal for next week's discussion - I'd like to propose two topics:


1) Graphs

Graphs were on the table (and that’s why Datagraph/Dydra joined the working group) and it seems they now get pushed off the table again. An argument has been introduced about problems with graph term entailments and there are long standing reservations against strengthening named graphs to make them usable for semantically sound annotations. Both arguments however are rather sweeping and haven’t been properly discussed.

If we dismiss graphs alltogether and settle for statement level annotations, we’re falling prey to a new problem: we will never be able to provide clear guidance about when which annotation mechanism should be used, named graphs or some tbd triple based approach. The best we could do is to advice people to use only the new mechanism, creating two new problems: we would thereby invalidate a good part of the installed base of named graphs, and we would still lack a graph based approach to annotation (or does someone want to live in a world where _all_ annotations have to be made per statement?). We can’t just declare named graphs off limits for any sound modelling - that would amount to calling them ripe for deprecation. The RDF 1.1 WG left a note on what was done and what could be probable venues of future endeavours. That note should guide us, not unspecific fear of breaking some free-wheeling first generation implementations.

For such reasons I think it is important that we discuss this in some depth. Also, and in any case, I’d like to encourage Andy to provide more detail about the problems he sees w.r.t. the installed base of named graph implementations. The RDF 1.1 WG Note on dataset semantics discusses some, but it seems that he sees more.

I proposed to discuss the other graph-related aspect, graph term entailment, in a Semantics TF meeting this Friday. There hasn’t been any response to that, but I’m still hopefull. To pepper the request a bit: apparently Notation3 did get by with graph terms for more than 20 years already. Why are the problems that Peter laid out a problem for the semantic web? And why are they considered relevant enough to dismiss the enormous usability benefits that graphs bring? Can’t they be solved, or at least called off limits, without breaking something very basic? What would that be? And again, why didn’t it break Notation3? It seems to me that a bit of pragmatism would be adequate. This is the semantic web, and logic in this context should be a means to an end - no less, no more. 


2) Basics

There is a lot of talk about abstract syntax and foramlizations (and I agree that the Nested Named Graph proposal doesn’t provide enough of both yet). However, there is also a glaring lack of a deeper understanding of the issues at hand. As I argued with Olaf this week, a formalization may be nice and pretty, but it is of little practical relevance if it doesn’t  formalize what’s actually needed. But there is very little discussion of what is actually needed in this WG, and there has been very little such discussion in the CG as well - I was even accused of stealing people’s time when I insisted on questioning the design of RDF-star as referentially opaque types. Many just _want to believe_ that there must be a simple solution and that we can force it into practice, declaring victory without actually winning. It’s a "don’t look up" approach where the winner - RDF-star - has already been crowned and now we just have to make it work somehow.  It won’t work. It will only undermine the credibility of W3C and the semnatic web standards suite.

RDF* had a basic design flaw from the beginning - targeting types instead of tokens - and the CG only made things worse with the proposed semenatics. This happens because there is no proper understanding, but more importantly not even a proper will to try to understand, the underlying design issues of meta modelling, namely that it has to target occurrences, that its semantics has to be very middle-of-the-road, that there should be no gap between the statement and its annotation (like the gap that all type-based approaches but even RDF standard reification introduce and that the OneGraph paper discusses w.r.t. to updates and deletes), and that it should be applicable to both singleton and sets. 

And then there is the question of the goal:
- RDF* was conceived as an alternative to verbose RDF standard reification. 
- the Berlin graph workshop aimed for RDF/LPG interoperability. 
- the issue of graphs in RDF has developped into a veritable trauma, but it is the elephant in the room: grouping stuff is the most basic knowledge representation activity thinkable, even more basic than graphs. A proper grouping mechanism will always be required. 
If we really settle for just one very minimal solution then IMO it has to be tailored to LPG interoperability. That certainly means tokens, not types, and it certainly means referential transparency. It also means singletons, but then again: it would be so easy to extend such a mechanism to sets that I really can’t see why we can’t do that too, and do everything right. That’s topic 1 again.



I know that many of you just want to go home and be done with it. Maybe it would be better to dissolve this WG without any result? Certainly better than doing something stupid.


Best,
Thomas

Received on Wednesday, 29 November 2023 22:34:18 UTC