On Tue, May 10, 2011 at 9:05 PM, Paul Houle paul@ontology2.com wrote:
On 5/10/2011 5:48 PM, Lars Aronsson wrote:
One thing that I would like to do in Wikipedia is:
A category that spans a scale, e.g. people by date of birth. Today we use [[Category:1823 births]] to group people born in that year, where the category page has links to the previous and next year, and possibly to supercategories by decade or century.
This gets to one of the big missing pieces of the semantic web, in my mind. I call them parametrized categories.
Let :L be some topic in DBpedia, and assume it's not one of the 1% or so bogus topics like "List of X"
If there is :L, then there's also a category which is :Books_About(:L) and if :P is a person, then there is :People_Who_Dated(:P). Then there are categories like :Metals_That_Melt_Between(1000C,1000C) and of course Union(:C1,:C2), Intersection(:C1,:C2)
It's all very nice but at some point you want to be reasoning about things rather than materializing zillions of categories that somebody might care about. Take a look at the bottom of
http://en.wikipedia.org/wiki/Arnold_Schwarzenegger
if you want to see the agony of Wikipedia categories. I mean, yikes! Why is one thing there and not another thing?
Once we've made the sin of materializing Intersection(c:American,c:Actor,c:Politician) why don't we also materialize Intersection(c:Actor,c:Politician,c:Athlete) and all the other combinations of the attributes that :Arnold_Schwarzenegger has?
What's particularly infuriating is that the categories are a badly denormalized rats nest. Is there some robot that goes around making sure that people who have a birth date in 1947 get listed in :1947_births and not in :1948_births? Wouldn't it make more sense to just code the birth date in a controlled manner and generate the birth year 'categories' on the fly?
And don't get me started on how the categories don't tile together. A few years back I wanted to make a list of automotive nameplates (c:Toyota_Corolla, c:Chevy_Mailbu) but there's no category that these all are in. You might find c:Models_of_Toyota_Cars, and c:Front_Wheel_Drive_Cars and c:Cars_That_From_A_Long_Distance_Look_Like_Flies and you need to merge these together and still edit out things that don't belong.) What a mess!
One of the advantages of using SMW over the present category structure would be to end the continual argumentation about what sorts of cross-categories are acceptable---in particular, to use the example of people, whether they should be categorized by ethnicity - profession intersections, e.g., American Jewish athletes. Unimaginable rancour arises from such discussions--see WP:Categories for Discussion at the enWP for examples.
At present they decision of whether or not to make a category is decided by the vague concept of presumed usefulness together with the inapplicable one of political correctness; there would be much to be gained by letting the user combine anything they might happen to want on the fly rather than have these pre-determined.