If one is interested in a functional “category” system, it would be very helpful to have a good logic-based ontology as the backbone.

I haven’t looked recently, but when I inquired about the ontology used by DBpedia a year ago, I was referred to “dbpedia-ontology.owl”, an ontology in the format of the “semantic web” ontology format OWL.  The OWL format is excellent for simple purposes, but the dbpedia-ontology.owl (at that time) was not well-structured (being very polite).  I did inquire as to who was maintaining the ontology, and had a hard time figuring out how to help bring it up to professional standards.  But it was like punching jello, nothing to grasp onto. I gave up, having other useful things to do with my time.

Perhaps it is time now, with more experience in hand, to rethink the category system starting with basics.   This is not as hard as it sounds.  It may require some changes where there is ambiguity or logical inconsistency, but mostly it only necessary to link the Wikipedia categories to an  ontology based on a well-structured and logically sound foundation ontology (also referred to as an “upper ontology”), that supplies the basic categories and relations.  Such an ontology can provide the basic concepts, whose labels can be translated into any terminology that any local user wants to use.  There are several well-structured foundation ontologies, based on over twenty years of research, but the one I suggest is the one I am most familiar with (which I created over the past seven years), called COSMO.  The files at http://micra.com/COSMO will provide the ontology itself (“COSMO.owl”, in OWL) and papers describing the basic principles.    COSMO is structured to be a “primitives-based foundation ontology”, containing all of the “semantic primitives” needed to describe anything one wants to talk about.   All other categories are structured as logical combinations of the  basic elements.  Its inventory of primitives is probably incomplete, but is able to describe everything I have been concerned with for years (7000 categories and 800 relations thus far) can always be supplemented as required for new fields.  With an OWL ontology, queries can be executed by any of several logic-based utilities.  Making the query system easy for those who prefer not to build SPARQL queries (including myself) would require some programming, but that is a miniscule effort compared to what has already been put into the DBPedia database.  Tools such as “Protégé” make it easy to work with an OWL ontology, and there is a web site where an OWL ontology can be developed collaboratively.

I will be willing to put some effort into this and assist anyone who wants to used the COSMO ontology for this project.   If those who are in charge of maintaining the ontology (is anyone?) would like to discuss this at greater length, send me an email or telephone me.  All those who are interested in this topic may also feel free to contact me, or to discuss this thread on the list.   I suggest the thread title “Foundation Ontology”.

Pat

Patrick Cassidy

MICRA Inc.

cassidy@micra.com

908-561-3416

From: wikidata-l-bounces@lists.wikimedia.org [mailto:wikidata-l-bounces@lists.wikimedia.org] On Behalf Of Michael Hale
Sent: Saturday, May 04, 2013 2:57 AM
To: Discussion list for the Wikidata project.
Subject: Re: [Wikidata-l] Question about wikipedia categories.

I think it's important to consider the distinction between a category system and semantic queries. I think it's very likely that DBpedia and Wikidata will converge over time and develop a simple enough query interface that causes fewer people to use the category system because we will be able to automatically generate relevant queries related to a given article. DBpedia currently has a lot more data, but Wikidata is important for many editing scenarios. Also, in the future I think there will be a lot of content scenarios where it is natural to start by putting data into Wikidata and then including it in articles instead of just extracting information from articles. If you are familiar with query languages you can get comfortable with the DBpedia SPARQL examples in a few minutes, but for a typical reader that just wants to go from an article about a person to a list of similar people it is hard to beat scrolling down and just clicking on a category. I did a test query on DBpedia to plot all sports cars by their engine sizes, and I think for the types of things it enables you to do it is totally worth the learning curve. That being said, I think the category system has a lot of potential for better browsing scenarios as opposed to queries. I've been making a tool that mixes the article view data with the category system. You can see a video of the basic idea here and a screenshot of football league popularity split by language. http://en.wikipedia.org/wiki/User:Wakebrdkid/Popular_category_browsing I'm currently multiplying the Chinese traffic by 30 to try and account for Baidu Baike.

> Date: Sat, 4 May 2013 08:14:54 +0200
> From: jane023@gmail.com
> To: wikidata-l@lists.wikimedia.org
> Subject: Re: [Wikidata-l] Question about wikipedia categories.
>
> Wondering exactly the same thing - my frustrations with categories
> began about three years ago and it seems I am surprised monthly by
> severe limitations to this outdated apparatus. I am a heavy category
> user, but I would love to be able to kick it out the door in favour of
> a more structured method. As far as I can tell, there is very little
> synchronisation among language Wikipedias of category trees, and being
> able to apply a central structure to all Wikipedias through Wikidata
> sounds like a great idea, and one which would not disturb the current
> category trees we already have, but supplement them. As I see it, some
> category structures are OK, but when categories get big, people split
> them in non-standard ways, causing problems like this recent
> media-hype regarding female novellists. I think that it's great this
> is in the news in this way, because I am sure that most Wikipedia
> readers never knew we had categories, and this is a great introduction
> to them, as well as an invitation to edit Wikipedia.
>
> 2013/5/4, Chris Maloney <voldrani@gmail.com>:
> > I am just curious if there has ever been discussion about the
> > potential for reimplementing / replacing the category system in
> > Wikipedia with semantic tagging in WikiData. It seem to me that the
> > recent kerfuffle with regards to "American women writers" would not
> > have happened if the pages were tagged with simple RDF assertions
> > instead of these convoluted categories. I know, of course, that it
> > would be a huge undertaking, but I just don't see how the category
> > system can continue to scale (I'm amazed it has scaled as well as it
> > has already, of course).
> >
> > I am trying to learn more about wikidata, and have perused the various
> > infos and FAQs for the last two hours, and can't find any discussion
> > of this particular issue.
> >
> > -- Chris
> >
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