Assassinator Wrote:Ok, lets start at the start.  Anime scores are not random, and certain shows everyone considers "good" while certain other shows everyone considers "poo poo", and so that will almost always give you positive correlation.  What I'm proposing is that wee standardize your score for each particular show with the sample for that show, so it removes the "quality element" of the show, and puts all shows on equal footing.  Then do the correlation.

Linear or not, it's directionally the same.  But what you're proposing could have issues such as overstating directional inconsistency.
To give a basic example, say A rates "good show" 8 and "bad show" 4, B rates "good show" 9 and "bad show" 3.  If wee do a simple scale to the mean, and say the mean of "good show" is 8.5 and "bad show" is 3.5, A would have scaled scores of -0.5 and +0.5 and B would have +0.5 and -0.5 which would be negatively correlated - probably not what you want.

If that's what you're trying to say.

Assassinator Wrote:You need to find the mean and SD of the sample, then find your z-score.  Mean and z-score aren't that hard, but finding the standard deviation probably might get intensive?

Oh, SD calculations are probably stuck on O(n) time.  People don't watch anime every 2 seconds, so you could probably update it when someone votes.  If that's too much, can always perform staggered updates (ie refresh every hour).

But is it possible to keep a running SD?
EDIT: just tried, yes, possible to keep a running SD - you need to store the sum of differences squared - this can be updated with a few (constant time) calculations when a new vote arrives.

(This post was last modified: 02/11/2009 06:57 PM by Assassinator.)