The position of users and items in the user x item occurrence matrix are interchangeable. For every solution problem that matches items to users, there is a dual solution that matches users to items.
In any case, log-likelihood methods in recommendation usually are applied to the item cooccurrence matrix to get an item-based recommendation algorithm. On Wed, Jul 28, 2010 at 9:49 AM, Tanton Gibbs <[email protected]>wrote: > Very cool, I didn't realize it handled item similarity alongside user > similarity. >
