list of recommendations without outdated (old) items

Question

i couldn't find any info on this anywhere.

i have a setup of users and items, where the items could became outdated pretty fast (in days). this means, i cannot show those items anymore, since the customer (who sells items) has no credit left and we don't know whether he plans to continue working with us (by charging more credit).

but i want to keep the user-items settings, because it is still valuable and the results are good. i'm afraid, that when getting e.g. 20 recommendations for a user, 15 out of 20 recommended items could be outdated.

is such a situation covered within mahout/myrrix, or do i have to implement my own filtering method via rescorerProvider (setting higher threshold for active items) or simply get 40 recommended items and filter first 20 of them which are still active?

there's one more solution that comes to my mind - erase old items from the user-item preference and put them as tags via the method http://myrrix.com/rest-api/#setusertag

Answer 1

That situation is not explicitly covered by either, in both you will have to introduce some custom logic.

Either solution you described should work (rescorer or generating more). However in my Myrrix you can use the pluggable CandidateFilter

I'm not so sure about the tagging trick, it might work since the tags act as pseudo users or pseudo items.