Re: Parameter choice and tuning parallelALS

2013-01-02 Thread Sean Owen
You can ignore alpha. In the implicit feedback version, the loss function weights squared errors for each cell differently. The weight is "1 + alpha * r" where r is the user-item value (could be a rating) and is usually a positive integer. alpha is high-ish, like 40 in the paper. So it suggests tha

Re: Parameter choice and tuning parallelALS

2013-01-02 Thread Sebastian Schelter
Hi Pat, ParallelALSFactorizationJob actually implements two different flavours of matrix factorization, one that is aimed at explicit feedback data (such as ratings): "Large-scale Parallel Collaborative Filtering for the Netflix Prize" [1] and another one that is aimed at using implicit feedback

Parameter choice and tuning parallelALS

2013-01-02 Thread Pat Ferrel
What is the intuition regarding the choice or tuning of the ALS params? Job-Specific Options: --lambda lambda regularization parameter --implicitFeedback implicitFeedback