Peer review

(I am not very familiar with machine learning, so that I might say something very stupid.)

First of all, as usual, your writing is very clear, which I like.

I suppose that the two approaches you discussed in the entry are not related but address the same research problem (scalable recommender system, roughly speaking). Did Salakhutdinov et al got motivated by some perceived limitation of Sarwar et al? I guess that the former said something in the previous works section about SVD in "advertising" their own approach?

Also, you mention some difference in the error patterns in the evaluation section. Maybe it is not relevant in establishing the advantage of RBM, but you could elaborate it a little -- I am just curiuous of the cause.