Keywords, Interest, Pr

I like the Keywords function. It's essential. I can even live with the fact that in the columnpicker it is called Interest. (Why not Keywords?) But what the hell is Pr? Page ratio or something? I know the problem is with me, but I haven't been able to figure it out for days now. Can somebody enlighten me?

Re: Keywords, Interest, Pr

I assume the field means the "Pr"obability that you will find the article interesting. This probability is computed using a Bayesian filter. How it knows whether you find an article interesting, however, is not clear to me.