Wikipedia Categories for Posters

I'd planned to extend the Alphabet maker into a site that assisted Charlie to find appropriate names by inducing the category of terms and then either warning about names not in the category, or correcting spelling based on names in that category, or even suggesting a name for a missing letter.

First I thought I should understand the categories available in dbPedia and started with the Wikipedia categories using the skos vocabulary . I wrote a small skos-based browser:

http://www.cems.uwe.ac.uk/xmlwiki/RDF/skosbrowse.xq?action=help

This has two pages: a category page showing the category, the list of resources in that category with broader and narrower categories and a resource page showing the English abstract and the Wikipedia thumbnail if there is one.

From a category, you can link to a gallery of all thumbnails for resources in that category, and hence to a random Alphabet poster based on that category. There is a significant proportion of dead links among the thumbnails however and I need to look-ahead to exclude them.

One feature of this application which I haven't seen elsewhere (I live a sheltered life!) is the use of key-bindings to perform common searches on selected text. Text selected in the abstract can, with one key-stoke, link to Wikipedia, Google, Google Maps or Google Images. I like the idea of giving more control to the user over what is linked, and I have implemented this on my prototype presentation software which I'm trialling on a couple of courses to see if students find this useful.

Browsing around dbPedia using Wikipedia categories and foaf:depiction is not without its problems. For example the category Amphibians includes:

• common names of amphibians - Cave Salamander
• species of amphibians - Gerobactrus
• groups, families and orders of Amphibians - Oreolalax
• parts of amphibians - Vocal Sac
• lists of amphibians - List of all Texas amphibians
• lists of related subjects - Federal Inventory of Amphibian Spawning Areas

This puts me in mind of Borges' invention of a Chinese classification of animals. Aren't categories like "suckling pigs" and "those that from a long way off look like flies" just delicious? However, erhaps a subject's other categories might help but there is no "List" category for example, so no way to disambiguate the various usages of a category.

foaf:depiction has a similar problem. The Modern Painters category shows a equal mixture of depictions of the painter and depictions of works by the painter, with a few depictions of where the artist lived. This is particularly confusing when the image is a portrait! However, these categories are much cleaner than others, if somewhat incomplete.

It has often been observed that tools based on dbPedia should help to improve Wikipedia. For example it is clear that the Painters by Nationality
should not have any Painter resources, so it would be nice to use this interface to edit the categories of the two errant painters directly from an interface like this.

Football Teams, DBPedia and SPARQL

Having written a number of applications which scrape information directly from Wikipedia pages, I was delighted to discover the DBpedia project. Chris Bizer and his collegues have brought the rather nebulous ideal of the Semantic web to life with this RDF database built on extracted data from Wikipedia, browsable as linked data or queryable with SPARQL. With this resource, I see how to contrast triples and SPARQL with SQL and XML in the DSA course.

My first experiment has been to try to answer a question that has been recently prompted, in part, by the appointment of Fabio Capella as the manager of the England Football team. My godson Oliver and I were wondering just how international our club sides are and what better way to find out than to use the DBpedia data to create a map of the birthplaces of the players in a team.

The result is described in some detail in an XQuery Wikibook article.
Here for example are the players in the Bolton Wanderers team shown via GoogleMap. (you may have to refresh - there's often an initial server error ??)

Being based on an extract from Wikipedia some weeks ago, this data is not quite up-to-date, there is missing data and inconsistancies in property tagging but I couldn't do this without DBpedia - thank you guys.