Re: (near) real time recommender/predictor

2013-02-02 Thread Pat Ferrel
RE: Temporal effects. In CF you are interested in similarities. For instance in a User-based CF recommender you want to detect users similar to a given user. The time decay of the similarities is likely to be very slow. In other word if I bought an iPad 1 and you bought an iPad 1, the

Re: (near) real time recommender/predictor

2013-02-02 Thread Ted Dunning
Pat, This is an important effect and it strongly informs how you should down-sample heavy users as well as how you should handle temporal dynamics. On Sat, Feb 2, 2013 at 9:54 AM, Pat Ferrel pat.fer...@gmail.com wrote: RE: Temporal effects. In CF you are interested in similarities. For

Re: (near) real time recommender/predictor

2013-02-02 Thread Pat Ferrel
Indeed, please elaborate. Not sure what you mean by this is an important effect Do you disagree with what I said re temporal decay? As to downsampling or rather reweighting outliers in popular items and/or active users--It's another interesting question. Does the fact that we both like

Re: (near) real time recommender/predictor

2013-02-02 Thread Ted Dunning
On Sat, Feb 2, 2013 at 1:03 PM, Pat Ferrel pat.fer...@gmail.com wrote: Indeed, please elaborate. Not sure what you mean by this is an important effect Do you disagree with what I said re temporal decay? No. I agree with it. Human relatedness decays much more quickly than item popularity.

(near) real time recommender/predictor

2013-01-31 Thread Frederik Kraus
Hi Guys, I'm rather new to the whole Mahout ecosystem, so please excuse if the questions I have are rather dumb ;) Our problem basically boils down to this: we want to match users with either the content they interested in and/or the content they could contribute to. To do this matching we

Re: (near) real time recommender/predictor

2013-01-31 Thread Sean Owen
It's a good question. I think you can achieve a partial solution in Mahout. Real-time suggests that you won't be able to make use of Hadoop-based implementations, since they are by nature big batch processes. All of the implementations accept the same input -- user,item,value. That's OK; you can