Tuesday, February 23, 2010

OpenCyc + Wiki/DB-Pedia and Ancient World References

This is another post in the Ancient World RDFa series.

I'm writing now because I have two questions in mind, one fairly general and one very specific:
  • Is there a pre-existing ontology that I can use to identify concepts found in Ancient World scholarship?
  • How can I indicate the office of "strategos" that was held by the sophist Polemon.
The topic comes up because I'm faced with the sentence fragment:
Polemon also appears as strategos on coins of Hadrian...
Again, how to mark the text "strategos" so that it is identified as the ancient office. Here's what I have so far:
typeof="skos:Concept opencyc:PublicOffice"
That give the following RDF/Turtle
a opencyc:PublicOffice, skos:Concept ;
owl:sameAs dbpedia:Strategos ;
rdfs:label "strategos"@en .
In short, this says that there's an instance of a public office and that office is "strategos".

The "opencyc" namespace maps to "http://sw.opencyc.org/". You can read about OpenCyc at http://www.opencyc.org, where you'll be told that OpenCyc is an "ontology containing hundreds of thousands of terms, along with millions of assertions relating the terms to each other, forming an ontology whose domain is all of human consensus reality." Even accounting for "commericial-speak", this could be useful. And yes, it's based on a commercial product, but CC-Licensed versions of the whole thing can be downloaded from http://www.opencyc.org/downloads.

The landing place for PublicOffice is http://sw.opencyc.org/2009/04/07/concept/en/PublicOffice. "Mayor" and "Ambassador" are example instances of PublicOffice so I'm comfortable using it as the type for Strategos. But "Strategos" iteself is not in OpenCyc. I think this will be a common situation: knowledge bases intended for the modern world will have many useful analogs for concepts that appear in Ancient World scholarhip, but the specific vocabulary will be missing.

OpenCyc has entries forYou can replace many narrowly scoped namespaces with these and other concepts that appear in OpenCyc.

But again, no "Strategos". This is where Wikpedia (via DBPedia) comes in. Here's the Wikipedia article. I map that into the Semantic Web via DBPedia.

So here's a basic principle: OpenCyc is the default ontology, DBPedia is the default vocabulary. I think that plays to the strengths of each resource.

Neither is complete for the Ancient World. That's probably more of a problem for the use of OpenCyc. DBPedia doesn't have a page for the ceramic type "Eastern Sigillata A". If I write one for Wikipedia, that will eventually migrate to DBPedia. OpenCyc doesn't have an easy route for community-based editing. Will the concepts "Excavation Unit" or "Survey Collection Unit" be necessary? Probably. That means coming up with or finding an ontology for those.


SnideGuy said...

Very nice description of why one should use OpenCyc and how. Cycorp is aware of the need for better coverage in the "leaves" of the ontology, and has tools in preparation to help users add them. Even Strategos.

Cliomatix said...

Oh my goodness, we need to talk :)

I am totally interested in semantic markup of historical evidence of any sort. My route to there is via the modeling of the logical structure of historical arguments (which hopefully bottoms out in evidence ...). So tagging the symbolic elements of archaeological finds is clearly proximate enough.

Here is a link to a project that I work on when family time permits, with some of the papers I have co-authored on this problem.

When I started on this in 1998, there was no OpenCYC yet, so I joined Cycorp instead. (I am actually the one who makes the OpenCYC releases ....)