You can also give ensemble blending a go http://videolectures.net/kdd2010_jahrer_cpar/
On 19 Sep 2012, at 16:27, Alejandro Bellogin Kouki wrote: > I think this problem relates with the one in Information Retrieval of "rank > aggregation". In the following paper you can find an example applied to group > recommendation: > http://www.inf.unibz.it/~ricci/papers/fp14-baltrunas.pdf > <http://www.inf.unibz.it/%7Ericci/papers/fp14-baltrunas.pdf> > > As Sean has explained, an average of the ratings is valid when the ratings to > be combined are in the same range, although probably Borda count or the > Spearman footrule are more common. > > When that is not the case, a normalization step is required: > http://ciir.cs.umass.edu/pubfiles/ir-242.pdf > A standard or rank-sim normalization step should be OK. > > Regards, > Alejandro > > Sean Owen escribió: >> If the output of the recommenders are estimated ratings then they are >> comparable. You can take the union of all top N lists. Then ask each >> recommended for an estimated rating for each it did not score already. >> Average the ratings and rank on that or perhaps average minus standard >> deviation. >> >> Most recommenders based on rating do this. Those not based on rating don't >> and it is not necessarily true that values are meaningfully comparable. >> Then you would have to make up a comparable score based on rank. I would >> use .5 for first, .25 for second, etc. Then follow the process above. >> >> Sean >> On Sep 19, 2012 3:49 PM, "yamo93" <[email protected]> wrote: >> >> >>> Hi, >>> >>> I try to make hybrid recommendations. So, I run different recommenders >>> (with different similarity algorithms) and I want to mix results (each algo >>> returns a list of recommended items). It seems to be known as Mixed Hybrid >>> in the Burke Taxonomy. >>> >>> I thought about a simple transposition in the range 0..1 for each list of >>> recommended items and to compute the average. >>> >>> But the results are not necessarily distributed linearly (by ex. Cosine) >>> >>> Which are the best math functions to do this ? >>> >>> Is there an existing impl. in mahout or in another framework ? >>> >>> Thanks for your help, >>> Yann. >>> >>> >> >> > > -- > Alejandro Bellogin Kouki > http://rincon.uam.es/dir?cw=435275268554687 >
