This is also very dangerous because negative ratings often correlated much more tightly with what people like than with what they don't like. If the blending is done carelessly, you can wind up recommending everything except what the user likes (if the negative ratings overwhelm the positive in spite of the blending parameters) or you can wind up missing some very good stuff.
On Tue, Apr 27, 2010 at 12:46 PM, Jake Mannix <[email protected]> wrote: > Another approach would be, if you have a lot of negative feedback as well > as positive feedback, to train two models, both treating the feedback as > positive, > and then blend the results with a negative blending weight (i.e. subtract > off a > scaled multiple of the negative feedback recommendation score from the > positive feedback recommendation score). > > This would only work if you had enough negative feedback to build an full > model out of it. > > -jake > > On Tue, Apr 27, 2010 at 11:43 AM, Ted Dunning <[email protected]> > wrote: > > > Boolean recommendations makes the assumption that either negative > feedback > > is really positive feedback (controversial, but works reasonably) or that > > negative feedback is not very useful (also controversial, but actually > > generally true). > > > > If you really want to use negative information soundly, you need to use a > > much fancier algorithm. This can lead to huge costs in CPU and memory > and > > it may or may not help you. More practical is to use boolean > > recommendations for the positive side and then just add a few heuristics > > for > > the negative side. Typical heuristics include: > > > > - don't show items that a user has negatively rated (obviously) > > - don't show items from a source that the user has rated negatively > > several times without rating other items from that source positively > > > > > > On Tue, Apr 27, 2010 at 10:27 AM, Tolga Oral <[email protected]> > wrote: > > > > > We are building a system on top of provided recommendations allowing > user > > > to > > > provide feedback. I have a question on how to apply the negative > feedback > > > for both boolean and none boolean scores. > > > > > > Assuming its a boolean item (item with no score), I cant see how we can > > > provide negative feedback for a given recommendation. Does this mean we > > > should convert our boolean items to a score of 1 and give score of -1 > (or > > > 0) > > > for recommendations that user didnt like? > > > > > > This applies to items with score too I am not sure if the correct way > of > > > going about this is to provide 0 or a negative value. > > > > > > Thank you. > > > > > >
