Machine learning

Computers can learn from facts.

They look at many examples to learn. This helps them do tasks on their own. It is like how you learn new things.

One way is to use a teacher. A human shows the computer what to do.

This helps the computer get better.

Another way uses a reward. The computer tries things to see what works.

This is like playing a game.

Some computers find patterns by themselves. They look for things no one knew before.

These smart tools are used every day. They help us solve many problems.

Computers can learn without being told every step. This is called machine learning. It is a part of artificial intelligence.

In this field, we use math to study data. The goal is to help computers do tasks on their own. They use what they learn to solve new problems.

Some tools use neural networks. These are groups of nodes that act like tiny artificial neurons. They help computers share data.

There are three main ways computers learn. First is supervised learning. This uses a teacher to help the computer.

Second is unsupervised learning. Here, the computer finds patterns by itself. Third is reinforcement learning. In this way, the computer learns by making decisions.

Arthur Samuel helped start this field in 1959. He made a program to play checkers. It could figure out its own winning chances. Today, machine learning helps us make sense of big sets of data. It can even help computers win games against humans.

Machine learning is a special way of studying computers. It is a part of artificial intelligence.

This field uses math to help computers learn from data. The goal is to help them do tasks without being told every single step.

Instead of following exact instructions, the computer looks for patterns. It uses these patterns to handle new information it has never seen before. This ability to use old lessons for new tasks is called generalization. This makes computers much more useful in our world.

There are three main ways that these machines learn.

The first way is called supervised learning. In this method, the computer uses a teacher to learn tasks like classification. The second way is unsupervised learning. Here, the computer finds its own patterns in data through things like clustering. The third way is reinforcement learning.

In this style, the computer learns by making decisions. It tries to do well based on its past actions. This helps it learn how to act in different situations.

People have been working on this for a long time. Arthur Samuel coined the term "machine learning" in 1959. He worked at IBM and was a pioneer in computer games. He made a program that could calculate winning chances in checkers.

Earlier, in 1949, a psychologist named Donald Hebb wrote about how nerve cells interact. His ideas helped scientists build artificial neurons. These are small nodes that allow computers to communicate data. These ideas laid the groundwork for how modern machines work today.

Many researchers have added to this history. In the 1960s, a company called Raytheon made a machine named Cybertron. It used a "goof" button so a human could tell it when it was wrong.

In 1981, researchers taught a network to recognize 40 different characters. These included 26 letters and 10 digits. By 2014, Ian Goodfellow and others created new ways to make realistic data. In 2016, a program named AlphaGo beat top human players. It used reinforcement learning to win its matches.

Machine learning is linked to many other types of science. It is a subset of artificial intelligence.

It also shares many tools with a field called statistics. While statistics looks at small samples, machine learning finds patterns to make predictions. It is also close to data mining. Data mining looks for unknown secrets in data, while machine learning predicts things based on what it knows. These different tools all help us understand the huge amount of information in our world.

Machine learning is a specialized field of study within artificial intelligence.

It focuses on creating statistical algorithms that can learn from data. These algorithms allow computers to perform tasks without explicit programming instructions. Instead of following a rigid script, the machine identifies patterns. It then uses those patterns to generalize to unseen data. Generalization is the ability to perform accurately on new examples after training. This process makes machines much more flexible than traditional software.

To understand how it works, we must look at the mathematical foundations. Machine learning relies heavily on statistics and mathematical optimization. Optimization is a method used to find the best solution among many options. Many algorithms work through a process called empirical risk minimization. This means the machine tries to reduce the error in its own predictions. It compares its guesses against actual results to find discrepancies. These discrepancies are often measured using a loss function. The machine then adjusts itself to minimize that loss over time.

Modern machine learning is categorized into three main types of algorithms.

The first is supervised learning, which uses labeled data to achieve goals like classification or regression. Classification assigns items to specific categories. Regression predicts continuous numerical values. The second type is unsupervised learning. This method finds hidden structures in data through clustering or association rules. It does not use pre-labeled answers. The third type is reinforcement learning.

This type focuses on making decisions based on previous, unknown time steps. It involves an agent interacting with an environment to achieve a goal.

The history of this field is rooted in human cognitive science. In 1949, psychologist Donald Hebb described how nerve cells interact in the brain.

His work provided a model for artificial neurons, which are nodes used in computers. These nodes allow data to communicate through a network. In 1959, Arthur Samuel coined the term "machine learning" while working at IBM. He created a program that could calculate winning chances in checkers. By the 1960s, the Raytheon Company developed Cybertron. This experimental machine used reinforcement learning to analyze speech and sonar patterns. It even featured a "goof" button for human teachers to signal errors.

Research continued to evolve through several decades of discovery. In 1981, researchers used neural networks to recognize 40 different characters. These included 26 letters, 10 digits, and 4 special symbols. In the mid-1980s, researchers like Geoffrey Hinton helped reinvent backpropagation. This allowed neural networks to learn more effectively. Later, in 2014, Ian Goodfellow and others introduced generative adversarial networks, or GANs. These are used for realistic data synthesis. A major milestone occurred in 2016 when AlphaGo defeated top human players. It used reinforcement learning to master the complex game of Go.

Machine learning is closely connected to other scientific disciplines. It is a subset of artificial intelligence, which is itself a broader field.

It also shares many methods with data mining. While they overlap, their goals differ. Machine learning focuses on prediction based on known properties. Data mining focuses on discovering previously unknown properties within a dataset. Additionally, machine learning relates to statistics. While statistics often draws inferences from a sample, machine learning seeks generalizable predictive patterns. Some scientists even combine these into a field called statistical learning.

Understanding the limits of these systems is an active area of research. One challenge is the balance between model complexity and data. If a model is too simple, it results in underfitting. This means it cannot capture the underlying patterns of the data. If a model is too complex, it may result in overfitting.

Overfitting happens when a machine learns the random noise in the training data rather than the actual pattern. Researchers use the bias-variance decomposition to quantify these errors. By managing this balance, scientists create more accurate and reliable machines. This continuous refinement helps machine learning tackle increasingly practical and complex problems.