Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Policy Gradients   The goal of policy gradient approaches is to find a policy in a given class
of policies which maximizes the expected return. Given a differentiable model
of the policy, we want to apply a gradient-ascent technique to reach a local
optimum. We mainly use gradient ascent, because it is theoretically well
researched. The main issue is that the policy gradient with respect to the
expected return is not available, thus we need to estimate it. As policy
gradient algorithms also tend to require on-policy data for the gradient
estimate, their biggest weakness is sample efficiency. For this reason, most
research is focused on finding algorithms with improved sample efficiency. This
paper provides a formal introduction to policy gradient that shows the
development of policy gradient approaches, and should enable the reader to
follow current research on the topic.

21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess