Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Asymmetric Tri-training for Debiasing Missing-Not-At-Random Explicit
  Feedback   In most real-world recommender systems, the observed rating data are subject
to selection bias, and the data are thus missing-not-at-random. Developing a
method to facilitate the learning of a recommender with biased feedback is one
of the most challenging problems, as it is widely known that naive approaches
under selection bias often lead to suboptimal results. A well-established
solution for the problem is using propensity scoring techniques. The propensity
score is the probability of each data being observed, and unbiased performance
estimation is possible by weighting each data by the inverse of its propensity.
However, the performance of the propensity-based unbiased estimation approach
is often affected by choice of the propensity estimation model or the high
variance problem. To overcome these limitations, we propose a model-agnostic
meta-learning method inspired by the asymmetric tri-training framework for
unsupervised domain adaptation. The proposed method utilizes two predictors to
generate data with reliable pseudo-ratings and another predictor to make the
final predictions. In a theoretical analysis, a propensity-independent upper
bound of the true performance metric is derived, and it is demonstrated that
the proposed method can minimize this bound. We conduct comprehensive
experiments using public real-world datasets. The results suggest that the
previous propensity-based methods are largely affected by the choice of
propensity models and the variance problem caused by the inverse propensity
weighting. Moreover, we show that the proposed meta-learning method is robust
to these issues and can facilitate in developing effective recommendations from
biased explicit feedback.

29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph