W3C home > Mailing lists > Public > semantic-web@w3.org > February 2009

Re: Extending RDFS, property-classes

From: Richard Newman <rnewman@twinql.com>
Date: Mon, 9 Feb 2009 21:32:06 -0800
Cc: Jiri Prochazka <ojirio@gmail.com>, semantic-web@w3.org
Message-Id: <AA8629A7-C364-44B4-B00D-2006D459B152@twinql.com>
To: Alan Ruttenberg <alanruttenberg@gmail.com>

> I find your remark very odd, and more demonstrative of a lack of
> experience than an accurate perception of the state or vision of the
> Semantic Web. Certainly the lack of customers using OWL becomes a
> self-fulfilling prophecy when such a point of view is held.

I was merely stating my experience: in my (... 6? Blimey.) years in  
the SW community, I'd say the ratio of organizations I've worked with  
using RDF for storage versus simple reasoning versus OWL reasoning is  
approximately 10:5:1. Granted, my recent work has been on a system  
that doesn't currently offer OWL reasoning (partly because of a lack  
of demand from customers: RDFS++ has been adequate), but we do stay in  
touch with a wide variety of people, including the RACER folks.

That's not to say that OWL *vocabulary* isn't used; after all, why  
bother making up your own sameAs property? I'm simply saying that  
folks trying to use OWL-DL (and up) reasoners on *real datasets and  
systems* (as opposed to things like my occasional playing around with  
Pellet) are significantly outnumbered by those dumping big datasets  
into RDF, and tooling for large-scale RDF systems is more widely  
available than tooling for OWL systems on the same scale.

The implication of that is that a solution in OWL 2 is not a solution  
for the majority of people: their tooling doesn't support it, or  
reasoning won't scale to their datasets, or they have to interoperate  
with others who aren't using it.


> OWL is widely deployed in the area I work on the Semantic Web for
> science, with our own Neurocommons being a 400M triple store expressed
> in OWL and many other projects using OWL.

Can I ask what level of reasoning you apply to Neurocommons?


> It would make no sense for any of these projects to use RDF or even  
> RDFS.

I wasn't saying anything of the sort.

If you scroll back and read what I wrote, I said:

* OWL 2 has annotations of assertions (yay!)
* I haven't heard of a single customer who is considering using OWL 2
* I don't know of any widespread deployments of OWL (the implication  
being "OWL reasoning", not "OWL vocabulary", which I would hope is  
obvious).

All of those things are true, and I'm not impugning OWL.

I would very much like to know about high-scale, high-traffic services  
being backed by OWL reasoning; knowledge of the industry is very  
interesting to me. Terascale reasoning would make some of my areas of  
interest much more straightforward!


> For one thing, the Semantic Web languages are aimed to be a set that  
> work together and
> build on each other. OWL will offer the first specified way of doing
> expressive annotations and it would make no sense to do other than use
> the facilities it offers, as owl:sameAs and owl:inverseFunctional are
> used now.

I will certainly investigate it. The reason I said this was something  
of a chicken/egg situation is that I can't see customers porting their  
*data* to OWL 2 without having tools to push it around. A language is  
useless without speakers.

-R
Received on Tuesday, 10 February 2009 05:32:45 GMT

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