What Is Reinforcement Learning?

Reinforcement learning (RL) is a subfield of machine learning that enables AI-based systems to execute actions through trial and error. RL can optimize collective rewards based on feedback received for individual activities. Feedback refers to a favorable or unfavorable perception expressed by incentives or penalties. In a nutshell, it is the act of programming a machine learning (ML) algorithm, robot, or another device to adapt to complex, real-time, and real-world settings in order to achieve a particular aim or outcome.

Examples of Reinforcement Learning

A potential example of RL is any situation in which an agent must interact with an unpredictable environment in order to achieve a certain objective. For example: 

Robots with pre-programmed behavior are effective in organized contexts, such as an automotive assembly line, where the activity is repetitive in nature. Pre-programming appropriate behaviors is difficult in the real world because the environmental response to the robot's activity is unknown. In such cases, RL provides an efficient method of building general-purpose robots. It has been effectively used in robotic route planning, which requires a robot to identify a short, smooth, and passable path between two places that are free of collisions and consistent with the robot's dynamics.

Another illustration of RL is the 3,000-year-old Chinese board game Go, which is one of the most difficult strategy games. The best human Go player was beaten in 2016 by an AlphaGo-based RL agent. It acquired knowledge via experience, just like a human player would, by competing in thousands of games against experts. The most recent RL-based Go agent has the capacity to improve by competing against itself, which gives it an edge over human players.

Common Reinforcement Learning Algorithms

Rather than referring to a single algorithm, reinforcement learning encompasses a number of algorithms that take different methods. The distinctions between methods include different approaches to explore their surroundings.

State-action-reward-state-action

This RL technique begins by providing the agent with a policy, which is a probability that informs the likelihood that particular activities will result in rewards or desirable situations.

Q-learning

This technique of Reinforcement Learning adopts a different strategy. The agent doesn't receive a policy, therefore the investigation of its surroundings is more independent.

Deep Q-Networks

Along with reinforcement learning strategies, these algorithms make use of neural networks. They apply RL’s self-directed environment exploration technique to  view a random sample of previous good behaviors to guide future action.

Challenges of Reinforcement Learning

The adoption of RL to solve business problems may bring up considerable challenges. The considered agent gathers data as it is required, since no labeled or unlabeled data exists to provide it with a task objective. The information acquired is impacted by the decisions taken. One of the main issues with reinforcement learning is the creation of simulation environments that are suitable for the task at hand. When the model must evolve into a superhuman at games like Go or Chess, setting up the simulation environment is quite simple.

Before permitting the autonomous car to travel on public roads, a realistic simulator for the model must be built. The RL model must identify how to stop or avert a collision in an environment where the cost of sacrificing a vehicle is negligible. The challenging part is transferring the model from the training environment into a tangible world. Another significant problem is scaling and modifying the neural network that controls the robot. Only the reward and punishment system is available as a means of communication with the network.

Additionally, it is challenging to constantly perform the appropriate actions in a real-world context due to how rapidly the environment changes. The time required to assure effective learning using this approach may restrict its utility and be demanding on computing resources. As the training environment becomes more sophisticated, so do the demands on time and computational resources.

Difference Between Reinforcement Learning and Supervised Learning

Supervised learning is a Machine Learning (ML) methodology that requires a skilled supervisor to curate a labeled dataset and feed it to the learning algorithm. The supervisor is in charge of gathering this training data, which is a collection of examples like pictures, text samples, or audio clips, each with a specification that allocates the sample to a given class. In the Reinforcement Learning (RL) scenario, this training dataset would seem like a collection of circumstances and behaviors, each with a 'quality' label attached to it. A supervised learning algorithm's primary job is to extrapolate and generalize, or to generate predictions about cases that are not included in the training dataset.

RL is a one-of-a-kind technique for machine learning. In contrast to utilizing a pre-labeled dataset, RL learns through experience gained by interacting with the environment. This critical distinction enables RL in complicated situations where it would be hard to pick labeled training data that is representative of all the conditions that the agent may experience. To be effective in these settings, training data creation must be autonomous and integrated into the learning algorithm itself, comparable to reinforcement learning.