Indeed. Train on the Oranges, test on the Greys.

Thanks! I think you're right, that in order to avoid fragmenting the site into a lot of different subclasses with different tastes that there could be a pool of "good" users who determine what the default "good" story and "good" post are.

I think you're subconsciously reinventing k-means clustering with random starting points.

Subclasses might not be such a bad idea at all actually, after all there are different coffee shops for different tastes as well. If a site could be made to automatically appear as a place that caters to your 'taste' that would be a pretty awesome development. Everybody would feel right at home.

This is a fair point.

Some people are here for startup stuff. Some people for codign/programming stuff. Yet others (though probably a smaller demographic) are here for social stuff. And more.

Plus others are here for a mix.

Some way to tailor what you see would be awesome! not too much that each "genre" is different but enough that the posts or articles you want to see are at the top :D

I know very little about statistics so I wouldn't have much of a clue about the right algorithm to use, but I do have a good idea of the behaviour I would like.

I think the behaviour I want is exactly that required by the Netflix Prize:

http://en.wikipedia.org/wiki/Netflix_prize

although rather than rating comments 1 to 5 I think I'd probably just have three levels (don't appreciate, neutral, appreciate).