> Can you correct me if so? This makes me doubt about the correctness of my point:) The best is possibly to write down a small example, with numbers and formulae. It's the best way either to see if I missed the point, or there is actually a subtle truth....
I'll soon get back to the group with something less abstract -thanks again! On Sun, Sep 21, 2014 at 10:06 PM, Ted Dunning <[email protected]> wrote: > On Fri, Sep 19, 2014 at 3:29 AM, <[email protected]> wrote: > > > So my question was -shouldn't we consider both the frequency distribution > > of item sales *and* of users purchases in the same formula? Am I correct > if > > I say that this does not happen when we compute the contingency table (if > > we build the contingency table for two users, we do not consider the > > frequency distribution of book sales, and vice versa), right? > > > > That said, I am fully aware that mine is a mainly academic question, as > the > > LLR makes anyway a fantastic job....! > > > > As I understand it, I believe that LLR does what your want since it knows > the overall frequency of the user and the item in question. > > What is does not do directly is include information about how *other* users > and *other* items are distributed except in aggregate. > > On the other hand, when you rank these LLR scores for a single user, you do > incorporate evidence from all other items (relative to that single user). > > I think that your point is actually quite subtle and I may have missed the > point. Can you correct me if so? >
