I am new to Mahout, and am still playing around with it.
My question is, is it appropriate to combine Item-Item and User-Item?
My use case is, a social networking application will try to recommend something for the current user based on user historical data (with higher priority), and combine the recommendation results from the current user's friends historical data (with lower priority), and display the result with ordered rating list.
The reason is, for example a new user might not have much historical data in the system, we can recommend something from his friends historical data. Once the user accumulate enough historical data, the recommendation should be based on more on that.
Is it appropriate to design system in this way?
Thank you for your time, George
This is fairly simple to write. You can create recommendations for the user, and then combine with recommendations for the other users. A dumb version of this logic would be to add: merge lists of recommendations by adding the scores for items that appear in both lists. Maybe you add N friends' recs together, and then add N times the user's own recs. You take recommendations from this list then.
This doesn't exist in the project per se but it's quite easy to write a method to do this on the List<RecommendedItem> that comes back from recommend().