Contents

## How do you define a state in Q-learning?

There are three basic concepts in reinforcement learning: state, action, and reward. The state describes the current situation. For a robot that is learning to walk, the state is the position of its two legs. For a Go program, the state is the positions of all the pieces on the board.

## What are the primary components of RL model?

Beyond the agent and the environment, one can identify four main subelements of a reinforcement learning system: a policy, a reward function, a value function, and, optionally, a model of the environment.

## Which is the correct definition of Q-learning?

Q-learning Definition Q* (s,a) is the expected value (cumulative discounted reward) of doing a in state s and then following the optimal policy. Q-learning uses Temporal Differences (TD) to estimate the value of Q* (s,a). Temporal difference is an agent learning from an environment through episodes with no prior knowledge of the environment.

## How is the Q table used in reinforcement learning?

The Q table helps us to find the best action for each state. It helps to maximize the expected reward by selecting the best of all possible actions. Q (state, action) returns the expected future reward of that action at that state. This function can be estimated using Q-Learning, which iteratively updates Q (s,a) using the Bellman equation.

## Why is Q learning considered an off policy?

It’s considered off-policy because the q-learning function learns from actions that are outside the current policy, like taking random actions, and therefore a policy isn’t needed. More specifically, q-learning seeks to learn a policy that maximizes the total reward. What’s ‘Q’?

## What are the Q values of a state?

Q-Values or Action-Values: Q-values are defined for states and actions. is an estimation of how good is it to take the action at the state. This estimation of will be iteratively computed using the TD- Update rule which we will see in the upcoming sections.