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:
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
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.