Is there anyway in the demo to see item recommendations, given another
item? I think my quick perusal of the code showed only userID as
input, but maybe I missed something. BTW, that's item-item
similarity, right? And that is usually calculated offline, right?
-Grant
On Mar 18, 2009, at 1:51 PM, Sean Owen wrote:
Yeah that's basically right. It lists the user's top ratings first,
recommendations second. Recommendations are based on all ratings in
the
model though, in theory.
Yes the example uses slope one internally. I like this algorithm
best as a
general default. It is easy to tweak the example to use something
else. It
is just another algorithm - works differently from the canonical
recommender
sketched in the documentation and no doubt gives different results.
On Mar 18, 2009 5:42 PM, "Grant Ingersoll" <[email protected]>
wrote:
Just to clarify, when I run the group lens demo, say with:
http://localhost:8080/mahout-taste-webapp/RecommenderServlet?userID=12&debug=true
I get something like:
User:User[id:12]
Recommender:
GroupLensRecommender
[recommender:CachingRecommender
[recommender:SlopeOneRecommender[weighted:true,
stdDevWeighted:true, diffStorage:MemoryDiffStorage]]]
Top 20 Preferences:
5.0 111 Taxi Driver (1976) Drama|Thriller
5.0 1198 Raiders of the Lost Ark (1981) Action|Adventure
5.0 1221 Godfather: Part II The (1974) Action|Crime|Drama
5.0 2804 Christmas Story A (1983) Comedy|Drama
...
Recommendations:
7.0 557 Mamma Roma (1962) Drama
5.5 2510 Just the Ticket (1999) Comedy|Romance
5.5 3295 Raining Stones (1993) Drama
...
Thus, what I am seeing here, is the preferences are the movies that
user 12
rated and which were then used to derive the recommendations listed
at the
bottom, right?
Also, it says I'm using a SlopeOneRecommender, what does that do
compared to
the other recommenders, as discussed in
http://localhost:8888/taste.html#examples? That is, is it
appropriate to
substitute in the other ones for this demo? Would it be worth
updating the
demo to show the results of the various recommenders?
Thanks
Grant
