Lesson 305

Reinforcement Learning

Agents · Rewards · Q-Learning

1:00

How an agent learns optimal behaviour from scratch by acting in an environment, collecting reward signals, and backing credit through the Bellman equation.

By the end, you can

  • Describe the agent–environment loop and name what the environment returns after each action.
  • Contrast reinforcement learning with supervised learning and explain the credit-assignment problem.
  • Define state, action, reward, discount factor, policy, value function, and Q function in an MDP.
  • Explain what the Markov property implies about the agent's memory requirements.
  • Compute a discounted return given a sequence of rewards and a gamma value.
  • Apply one step of the Q-learning update formula given Q, alpha, r, gamma, and max Q(s').
  • Explain why Q-learning is model-free and off-policy.
  • Describe how the Bellman equation propagates value backward from a goal.
  • Explain what Deep RL adds and name at least two landmark applications.
Up next in AI, Machine Learning & Course Review
Questions or feedback?