DISQUS

John Goodwin · 1 year ago

I don't know how hard it is, but it would be nice to see more explanations for inconsistencies in the ABox. I recently converted some legacy data to RDF, and with the help of Topbraid, Pellet and a simple OWL ontology I managed to find errors in the data...these errors being highlighted as an inconsistency in the ontology.

Kendall · 1 year ago

Hi John...My next post in this series will be about how explanation -- as a reasoning service -- provides all sorts of real-world benefits, including, as you point out, providing quite good "debugging hints" when you find problems in data.

I will also be hammering the relative advantage OWL has in this regard over RDF and RDFS, which both are so weak that no explanations are ever useful because no RDF/RDFS inferences are ever useful (Okay, a bit of an exaggeration, but still...)

John Goodwin · 1 year ago

I've been toying with the idea of only excluding certain bits of the OWL ontology when it comes to checking consistency, but then removing them when it comes to implementing the RDF. For example in some cases "allValuesFrom" restriction might be useful for TBox and ABox consistency checking, but might add little when it comes to querying while also making the reasoning less tractable. Any thoughts?

Kendall · 1 year ago

I assume you meant "including" rather than "excluding" in the sentence.

Generally, I think identifying different data "facets" -- for lack of a better term -- and producing ontologies, or versions of an ontology, for each facet seems reasonable. It reminds me of the best practice from XML Land, where it's often said that a really complex apps needs several schemas.

The real trick is doing something clever in various reasoning systems to support this kind of faceted work.

Since Owlgres, in particular for us, is considerably less expressive but more scalable, one might build a more maximal ontology to check consistency but something more minimal (or none at all) to do query. Sure.

Ideally this process could be at least semi-automated; but I'm not familiar with any work in this area, though more well-informed folks might know otherwise.

John Goodwin · 1 year ago

"Ideally this process could be at least semi-automated; but I’m not familiar with any work in this area":

Well another project for Bijan to start if that is the case :)