This is nice. As you say, k11 is the only part that is used in cooccurrence and it doesn't weight by prevalence, either.
This size analysis is hard to demonstrate much difference because it is hard to show interesting values of LLR without absurdly string coordination between items. On Fri, Aug 16, 2013 at 8:21 PM, B Lyon <[email protected]> wrote: > As part of trying to get a better grip on recommenders, I have started a > simple interactive visualization that begins with the raw data of user-item > interactions and goes all the way to being able to twiddle the interactions > in a test user vector to see the impact on recommended items. This is for > simple "user interacted with an item" case rather than numerical > preferences for items. The goal is to show the intermediate pieces and how > they fit together via popup text on mouseovers and dynamic highlighting of > the related pieces. I am of course interested in feedback as I keep > tweaking on it - not sure I got all the terminology quite right yet, for > example, and might have missed some other things I need to know about. > Note that this material is covered in Chapter 6.2 in MIA in the discussion > on distributed recommenders. > > It's on googledrive here (very much a work-in-progress): > > https://googledrive.com/host/0B2GQktu-wcTiWHRwZFJacjlqODA/ > > (apologies to small resolution screens) > > This is based only on the co-occurrence matrix, rather than including the > other similarity measures, although in working through this, it seems that > the other ones can just be interpreted as having alternative definitions of > what "*" means in matrix multiplication of A^T*A, where A is the user-item > matrix... and as an aside to me begs the interesting question of [purely > hypotheticall?] situations where LLR and co-occurrence are at odds with > each other in making recommendations, as co-occurrence seems to be just > using the "k11" term that is part of the LLR calculation. > > My goal (at the moment at least) is to eventually continue this for the > solr-recommender project that started as few weeks ago, where we have the > additional cross-matrix, as well as a kind of regrouping of pieces for > solr. > > > -- > BF Lyon > http://www.nowherenearithaca.com >
