Accelerating exploration and representation learning with offline pre-training

Bogdan Mazoure, Jake Bruce, Doina Precup, Rob Fergus, Ankit Anand

Keywords: reinforcement learning, contrastive learning, offline pre-training, learning from demonstrations, nethack

TL;DR: We propose a contrastive pre-training scheme from human demonstrations for hard RL tasks.

Abstract: Sequential decision-making agents struggle with long horizon tasks, since solving them requires multi-step reasoning. Most reinforcement learning (RL) algorithms address this challenge by improved credit assignment, introducing memory capability, altering the agent’s intrinsic motivation (i.e. exploration) or its worldview (i.e. knowledge representation). Many of these componentscould be learned from offline data. In this work, we follow the hypothesis that exploration and representation learning can be improved by separately learning two different models from a single offline dataset. We show that learning a state representation using noise-contrastive estimation and a model of auxiliary reward separately from a single collection of human demonstrations can significantly improve the sample efficiency on the challenging NetHack benchmark. We also ablate various components of our experimental setting and highlight crucial insights.

Submission Number: 4