What is Reinforcement Learning?

Machine learning techniques like reinforcement learning (RL) let agents discover how to act in a given environment via trial and error. Unlike supervised learning, RL agents are rewarded or punished for their activities, where agents are trained on a labeled dataset of examples. Over time, RL agents must learn to optimize their rewards.

Playing games, operating robots, and overseeing intricate systems have all been accomplished with amazing results using RL, a potent new approach to AI. For instance, RL agents have mastered playing Atari games at a superhuman level, walking bipedal robots, and successfully trading stocks.

The Workings of Reinforcement Learning

A fundamental principle of RL is that agents learn through making mistakes. They take acts in the environment, and as a result, they are rewarded or penalized. The agents subsequently alter their actions to increase their rewards in the future.

The following steps can be used to summarize the RL process:

  • The agent is aware of its surroundings. This involves using sensors to monitor the environment’s condition, such as the location of other items or a system’s present state.
  • The agent decides on an action. This could be a chance occurrence or a learned behavior the agent uses to optimize its gains.
  • The agent executes the chosen action. A robot may need to be moved, a trade made, or a move in a game made.
  • The agent is rewarded or penalized for its deed. The environment sets this reward or punishment and often depends on the agent’s status before and after the activity.
  • The agent gains knowledge through experience. The agent updates its rules for choosing actions and understanding the environment. This procedure is repeated until the agent discovers how to act to maximize its long-term rewards.

Algorithms for Reinforcement Learning

There are numerous RL algorithms, each with unique advantages and disadvantages. RL algorithms that are well-liked include:

  • Q-learning: The Q-learning RL algorithm learns a Q-function, which converts state-action pairs into anticipated rewards.
  • SARSA: Similar to Q-learning, SARSA learns a Q-function that converts state-action-reward-next-state sequences into expected rewards.
  • Policy gradient algorithms: Without first learning a Q-function, policy gradient methods immediately learn a policy. Compared to Q-learning and SARSA, policy gradient algorithms are frequently more effective but can also be more challenging to implement.

Reinforcement learning applications

Numerous issues can be resolved via RL, including:

  • Playing games: Atari games, Go, and chess have all seen the usage of RL agents to achieve superhuman performance.
  • Robot control: RL agents can direct robots to run, walk, and pick up stuff.
  • Managing complex systems: RL agents can manage intricate designs, including transportation networks, financial markets, and electrical grids.

Problems with Reinforcement Learning

Although RL is a strong new approach to AI, it also has a lot of problems. One difficulty is that RL agents may need to learn by making costly and time-consuming mistakes. The fact that RL agents may be sensitive to the reward function’s design presents another difficulty. The agent may learn to act in a not desired way if the reward function is not carefully defined.

Reinforcement learning in the future

Although there are difficulties, RL is a promising new direction in AI. The range of problems for which RL is used is expanding, and RL algorithms are getting more effective and reliable. Future developments in intelligent robotics and self-driving vehicles will rely heavily on RL.

Examples of Reinforcement Learning in Practice

RL is currently being used in the real world in the following ways:

  • RL is used by Google AI’s deep learning system AlphaFold to predict the three-dimensional (3D) structure of proteins. With previously unheard-of precision, AlphaFold has been able to predict protein structures, which may pave the way for new developments in the study of biology and the development of drugs.
  • Five real-world agents trained to play the difficult multiplayer video game Dota 2 make up the group known as OpenAI Five. The ability of RL to develop AI systems that can outperform humans at challenging tasks has been demonstrated by OpenAI Five’s ability to defeat the world’s top human Dota 2 players.
  • The robot arm created by DeepMind employs reinforcement learning (RL) to learn how to manipulate objects. The robot arm is known to carry out difficult tasks like folding laundry and stacking blocks without being specifically taught.


A powerful method for teaching AI agents to carry out various tasks is reinforcement learning. Although RL is still in its infancy, it has already produced outstanding outcomes in several fields. RL is predicted to play a bigger part in advancing artificial intelligence as RL algorithms get better and new applications are found.

Prathamesh Ingle is a Mechanical Engineer and works as a Data Analyst. He is also an AI practitioner and certified Data Scientist with an interest in applications of AI. He is enthusiastic about exploring new technologies and advancements with their real-life applications

🐝 Join the Fastest Growing AI Research Newsletter Read by Researchers from Google + NVIDIA + Meta + Stanford + MIT + Microsoft and many others...