owl

A rules language for RDF

Right under our noses.

Last May, in Adding semantics to make data more valuable: the secret revealed, I showed how storing a little bit of semantics about the word “spouse”—the fact that it’s a symmetric property (that is, that if A is the spouse of B, then B is the spouse of A)—let me look up someone’s home phone number in my address book even if my entry for him there lacks his home phone number. I like this story because unlike biotech and some of the other popular domains for Semantic Web…

Modeling your data with DBpedia vocabularies

Broad, useful, vocabularies with plenty of sample data.

I’ve known for a while about ways to dig into the vocabularies used in DBpedia’s massive collection of triples, and I’ve used terms from these vocabularies to query for information such as Bart Simpson blackboard messages and US presidents’ ages at inauguration. I saw these terms as “field” names to use when querying this body of data.

Writing about the Semantic Web

And Linked Data, and RDF, and RDFa, and SPARQL, and OWL, and...

After writing a few paid articles and doing a lot of blogging about various issues, features, and trends surrounding the Semantic Web, Linked Data, RDF, RDFa, SPARQL, OWL, and related tools and implementations, I thought it would be nice if I could tie them together into something resembling a cohesive whole. So, I wrote a short essay titled RDF, The Semantic Web, and Linked Data with over 70 footnote links to these various pieces. It will be a handy reference for me in the future, and I hope it…

Publishers and semantic web technology

A response to Dale Waldt's Gilbane XML posting on semantics and the web.

My old friend Dale Waldt (I remember, immediately after the announcement of the existence of XML at SGML 1996, going up to my then-coworker Dale and asking “So what do we think?") recently posted an entry on the Gilbane XML blog titled Why Adding Semantics to Web Data is Difficult. A few days ago I posted a comment saying that the things that he saw as missing from semantic technologies are actually already there and working well, but my reply hasn’t shown up yet, so after a bit…

Adding metadata value with Pellet

A nice new feature of Pellet 2.0.

The open-source program Pellet is described as an OWL reasoner, but I’ve used it mostly as a SPARQL engine that happens to understand OWL. So, for example, if I have RDF that says “Loretta’s spouse is Leroy and spouse is a symmetric property,” but the data makes no mention of Leroy’s spouse, and I ask Pellet “who is Leroy’s spouse,” it can give me the answer.