[adi92]

They are talking about Latent Dirichlet Allocation which was made by Blei in 2002 ( http://en.wikipedia.org/wiki/Latent_Dirichlet_allocation )

Here is video by him where he explains the basic model as well timeline-related hacks the article talks about - http://video.google.com/videoplay?docid=3077213787166426672#

You can very easily play with LDA yourself with this toolkit - http://mallet.cs.umass.edu/

[jkan]

I think they're talking about this one:

http://projecteuclid.org/euclid.aoas/1183143727

This work uses the correlated topic model, which extends LDA to model correlations among the extracted topics.

Edit: and this one [pdf]:

http://www.icml2010.org/papers/384.pdf

[jacques_chester]

Was I just looking at formulae or some pages taken from the Odyssey?

I guess we could get the computer to categorise it ...