Yes, you're trying to solve a slightly simpler problem than recommending items to users. You just want to find users similar to a given user.
Yes you di want the method UserBasedRecommender.mostSimilarUserIDs(). It's implemented at the moment by GenericUserBasedRecommender and others. An item-based recommender is based on item-item similarities, so it's not by nature suited to answer the question, which users are similar to a given user? It's user-based recommenders that can help you there. I don't think you want to swap users and items, no. Sean On Mon, Mar 1, 2010 at 9:53 PM, Steve McNewman <[email protected]> wrote: > > Hi Mahout Community, > I am currently playing around with the Taste and would like to get the > following working: Given a set of users who have used a certain item, I > would like to get a list of recommendations for the most similar users. As > far as I understand, both user- and item-based recommender return a list of > RecommendedItems when executing their recommend(userId, howMany) method. The > difference between them is that user-based recommender use (weighted) > user-similarities and item-based recommender (weighted) item-similarities, > right? > > How do I get the most similar user IDs? Do I simply use the > mostSimilarUserIDs(userId, howMany) method of the user-based recommender? > Why can't I use an item-based recommender for this? Do I need to use a > DataModel with swapped item and userIdColumns? In how far is the list of > most similar User IDs related to collaborative filtering?
