This is exactly what Rescorer is for in the recommend() method. Does that suit? On Nov 15, 2011 11:37 AM, "Anatoliy Kats" <a.k...@rambler-co.ru> wrote:
> Hi all, > > I have a use case for Taste where we should use all available items for > computation of user similarity, but only some items are eligible to be > recommended. The reason is that items expire: goods get discontinued, for > example. The fact that a user bought something now discontinued is > important for finding similar users, but we cannot recommend it. One way > of solving this is using mahout to generate recommendations, and then > post-process it to remove ineligible items. But this can run into > performance issues if the set of ineligible items is large. Also, the > evaluation framework is not designed to handle this kind of a restriction. > > I can contribute a patch, but since I am new to the project, I need some > help with the software engineering from the regular contributors. How > would I design the necessary classes? One idea I considered was using the > existing tools for candidate item strategy. This has two downsides: you > can only use one candidate item strategy at a time, so having an eligible > set would make it impossible to have a candidate item strategy. Also, the > evaluator doesn't take the candidate item strategy into account. So, I > suppose I could try writing an EligibleSetCandidateItemStrate**gy that > takes another CandidateItemStrategy and applies it as well, and I can add a > new evaluator that takes eligible sets into account. I don't know the > thinking behind the design, so I don't know if this is a good idea or not. > Can we agree on a design before I get started? > > Cheers, > > Anatoliy >
