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From Sean Owen <>
Subject Re: problems with GenericRecommenderIRStatsEvaluator:
Date Thu, 05 Nov 2009 13:33:50 GMT
On Thu, Nov 5, 2009 at 1:28 PM, michal shmueli <> wrote:
>>    - which recommenderEvaluator would you suggest for Boolean data? does it
> also mean that I need to change the recommender that i'm using (which use
> the Tanimoto similarity) ?

None of them will work with RecommenderEvaluator. It is trying to
evaluate how well estimated and actual preferences match, but, with
boolean data, these are all always 1, so it's meaningless. You are
doing the right thing.

>  - It seems that you give the same results if you report on the best-2
> (ranked 1st and 2nd) out of k=10 or the worst-2 (9th and 10th) from the 10,
> but again , I might be wrong.

What do you mean by 1st, 2nd, 9th, 10th? in your data set there is no
notion of an item being "most liked" by a user.

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