Hi, Taste is appropriate for scenarios where there are users and where these users have item preferences. But is it appropriate for scenarios where there are no users in the game? For example, instead of looking at item preferences of authenticated users, could you look at, say, Amazon shopping carts to figure out which books people buy together to arrive at the "People who bought Lucene in Action also bought Managing Gigabytes" recommendation? In other words, could you simply look at item-item correlation without paying any attention to users?
Based on http://lucene.apache.org/mahout/taste.html#Item-based+Recommender I'd think this is possible, but I looked at some of the classes mentioned in the example there, and they all have references to User objects. Does that mean item-item recommendations like in my example above are not possible with Taste? I do see GenericItemSimilarity.ItemItemCorrelation, but even there I see references to DataModel class which references the User class. Perhaps for item-item recommendations one can simply not use the ctors with the DataModel argument? Is that the idea? Also, is the idea that something (e.g. my app) calculates "correlatedness" (that float) of 2 Items and feeds that to GenericItemSimilarity.ItemItemCorrelation's ctor? If so, what exactly does GenericItemSimilarity.ItemItemCorrelation do? Doesn't it then simply serve the purpose of finding top N most correlated items for any given item? Actually, I see only this: public double itemCorrelation(Item item1, Item item2) So it's not really a structure that gives top N items for a given Item. Is there a way to get Taste to do that? If my app has to calculate how related 2 items are, then is there is a need for Taste in this purely item-item scenario? Thanks, Otis P.S. A few The doc on the site mentions ItemCorrelation, but there is no such class. There may be other missing classes, I didn't check closely. I saw this in the PearsonCorrelationSimilarity: * <p><code>sumXY / sqrt(sumX2 * sumY2)</code></p> * * <p>where <code>size</code> is the number of [EMAIL PROTECTED] Item}s in the [EMAIL PROTECTED] DataModel}.</p> Is that really "size"? Or should it be sumSomething?
