Abstract
In this work, we study the credit assignment problem in reward augmented maximum likelihood (RAML) learning, and establish a theoretical equivalence between the token-level counterpart of RAML and the entropy regularized reinforcement learning. Inspired by the connection, we propose two sequence prediction algorithms, one extending RAML with fine-grained credit assignment and the other improving Actor-Critic with a systematic entropy regularization. On two benchmark datasets, we show the proposed algorithms outperform RAML and Actor-Critic respectively, providing new alternatives to sequence prediction.- Anthology ID:
 - P18-1155
 - Volume:
 - Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
 - Month:
 - July
 - Year:
 - 2018
 - Address:
 - Melbourne, Australia
 - Editors:
 - Iryna Gurevych, Yusuke Miyao
 - Venue:
 - ACL
 - SIG:
 - Publisher:
 - Association for Computational Linguistics
 - Note:
 - Pages:
 - 1672–1682
 - Language:
 - URL:
 - https://aclanthology.org/P18-1155
 - DOI:
 - 10.18653/v1/P18-1155
 - Cite (ACL):
 - Zihang Dai, Qizhe Xie, and Eduard Hovy. 2018. From Credit Assignment to Entropy Regularization: Two New Algorithms for Neural Sequence Prediction. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 1672–1682, Melbourne, Australia. Association for Computational Linguistics.
 - Cite (Informal):
 - From Credit Assignment to Entropy Regularization: Two New Algorithms for Neural Sequence Prediction (Dai et al., ACL 2018)
 - PDF:
 - https://preview.aclanthology.org/ingest-acl-2023-videos/P18-1155.pdf
 - Code
 - zihangdai/ERAC-VAML
 - Data
 - MS COCO