  Recommendation from implicit feedback is a highly challenging task due to the
lack of the reliable observed negative data. A popular and effective approach
for implicit recommendation is to treat unobserved data as negative but
downweight their confidence. Naturally, how to assign confidence weights and
how to handle the large number of the unobserved data are two key problems for
implicit recommendation models. However, existing methods either pursuit fast
learning by manually assigning simple confidence weights, which lacks
flexibility and may create empirical bias in evaluating user's preference; or
adaptively infer personalized confidence weights but suffer from low
efficiency. To achieve both adaptive weights assignment and efficient model
learning, we propose a fast adaptively weighted matrix factorization (FAWMF)
based on variational auto-encoder. The personalized data confidence weights are
adaptively assigned with a parameterized neural network (function) and the
network can be inferred from the data. Further, to support fast and stable
learning of FAWMF, a new specific batch-based learning algorithm fBGD has been
developed, which trains on all feedback data but its complexity is linear to
the number of observed data. Extensive experiments on real-world datasets
demonstrate the superiority of the proposed FAWMF and its learning algorithm
fBGD.
