Machine Learning Algorithms - Second Edition

Reinforcement learning

Even if there are no actual supervisors, reinforcement learning is also based on feedback provided by the environment. However, in this case, the information is more qualitative and doesn't help the agent in determining a precise measure of its error. In reinforcement learning, this feedback is usually called reward (sometimes, a negative one is defined as a penalty), and it's useful to understand whether a certain action performed in a state is positive or not. The sequence of most useful actions is a policy that the agent has to learn in order to be able to always make the best decision in terms of the highest immediate and cumulative (future) reward. In other words, an action can also be imperfect, but in terms of ...