Similar to *which* item? It sounds like you are turning the classic recommender problem on its side. Given an *item*, find users who might like it. Yes, you can easily do that too, but by thinking of items as users and vice versa.
This is not what item-based recommenders do. On Fri, Feb 19, 2010 at 11:32 PM, jamborta <[email protected]> wrote: > > what about constructing a neighborhood of > similar items and consider users who rated the target item? > > something like this paper: > > http://portal.acm.org/citation.cfm?id=371920.372071 > > > > srowen wrote: >> >> It's an interesting question, and I think the quickest answer is -- >> what item would be the center of the neighborhood? how would you >> incorporate a notion of neighborhood? >> >> For users, it's clear: you construct ahead of time a neighborhood of >> similar users and consider item's they've rated. For item-based >> recommenders, this idea doesn't exist. >> >> It's easy to imagine new algorithms involving a neighborhood of items. >> Maybe I look at each item a user knows about, construct a neighborhood >> around that item and do something with it. These aren't canonical >> algorithms, but you could try them. >> >> Sean >> >> On Fri, Feb 19, 2010 at 10:51 PM, jamborta <[email protected]> wrote: >>> >>> hi, >>> >>> just wondering why there is no option to set the neighbourhood size for >>> item-based recommendation. I had a look at the implementation and it >>> looks >>> like you take into account all items. is there a reason for that? >>> >>> thanks >>> Tamas >>> >>> -- >>> View this message in context: >>> http://old.nabble.com/item-based-recommendation-neighbourhood-size-tp27661482p27661482.html >>> Sent from the Mahout User List mailing list archive at Nabble.com. >>> >>> >> >> > > -- > View this message in context: > http://old.nabble.com/item-based-recommendation-neighbourhood-size-tp27661482p27661852.html > Sent from the Mahout User List mailing list archive at Nabble.com. > >
