This kind of normalization is normally changed by changing the distance metric.
On Wed, Jul 13, 2011 at 11:34 AM, Sean Owen <[email protected]> wrote: > What kind of normalization do you have in mind? I can imagine many > variations on what it does now, each of which has some merit. > > Without ratings, the classic simple neighborhood algorithm is a bit > inapplicable: it relies on a weighted average of ratings, where > similarities > are weights -- but there are no ratings. So you have to rank based on some > function of the weights only (similarities). I think it merely sums now, > which is the simplest thing. > > On Wed, Jul 13, 2011 at 4:23 PM, Steven Bourke <[email protected]> wrote: > > > Hi - > > > > It looks like the boolean recommenders would benefit from some form of > > normalisation in the predictive stage of the recommendation algorithm. An > > item that is prominent in a users neighbourhood may lose out simply > because > > of a high similarity between two single users. > > > > I'm assuming there is a reason this hasn't been added previously, anyone > > know why? > > >
