Reinforcement Learning Lecture 5: Model-Free Control

David Silver’s Lecture 5. Finding the optimal policy without a model. Why action values rather than state values, the two doors and ε-greedy and GLIE, Sarsa and Sarsa(λ) on the windy gridworld, importance sampling and off-policy learning, Q-learning through cliff walking, and the correspondence between DP and TD.

January 16, 2021 · 14 min · rick

Information Geometry: How AI Learns Most Efficiently

Just as Newton’s F=ma describes the physical world, information geometry describes how AI learns. An intuitive guide for beginners.

January 9, 2021 · 4 min · rick

Reinforcement Learning Lecture 4: Model-Free Prediction

David Silver’s Lecture 4. Estimate the value of a policy from experience alone, with no model of the environment. Monte-Carlo in Blackjack, temporal-difference learning on the drive home, the unified view of bootstrapping and sampling, and TD(λ) with eligibility traces.

December 12, 2020 · 6 min · rick

Reinforcement Learning Lecture 3: Dynamic Programming

David Silver’s Lecture 3. When the MDP is fully known, solve the Bellman equations by iteration to compute the optimal policy. Policy evaluation, policy iteration, and value iteration through a small grid world example.

November 14, 2020 · 6 min · rick

Reinforcement Learning Lecture 2: Markov Decision Processes

David Silver’s Lecture 2. The Markov decision process is the container that holds the reinforcement learning problem, built up one layer at a time, from the Markov chain through the reward process to the decision process, alongside Silver’s ‘student’ example.

October 17, 2020 · 6 min · rick

Reinforcement Learning, Lecture 1: The RL Problem

David Silver’s lecture 1. What sets reinforcement learning apart from other kinds of learning, reward and state, and the three pieces that make up an agent (policy, value function, model).

September 19, 2020 · 12 min · rick

Reinforcement Learning: Sutton & Barto and David Silver, Free

The two best free ways into reinforcement learning: Sutton & Barto’s textbook (free PDF) and David Silver’s course (free videos). Where to get them, to open this series.

September 5, 2020 · 2 min · rick