2019

Minimax Weight and Q-Function Learning for Off-Policy Evaluation

Uehara, Masatoshi, Huang, Jiawei, Jiang, Nan

Understand

We provide theoretical investigations into off-policy evaluation in reinforcement learning using function approximators for (marginalized) importance weights and value functions.

  • Our contributions include: (1) A new estimator, MWL, that directly estimates importance ratios over the state-action distributions, removing the reliance on knowledge of the behavior policy as in prior work (Liu et al., 2018).
  • (2) Another new estimator, MQL, obtained by swapping the roles of importance weights and value-functions in MWL.
  • MQL has an intuitive interpretation of minimizing average Bellman errors and can be combined with MWL in a doubly robust manner.

Reading the bibliography…