training
Training is the process in which an AI model learns from countless examples, through gradual attempts and corrections, how to solve a task.
In plain terms
Traditional software is written rule by rule. An AI model is not written but trained: many examples are shown to it, and it identifies patterns on its own.
It is like when a child learns to ride a bicycle. They do not memorize physics formulas but wobble thousands of times, correct, and eventually get a feel for balance. The model guesses the same way, learns how big the error was, and adjusts itself slightly.
At the end of training, a finished model is produced whose "knowledge" is stored in a large number of configured values (parameters). In a large language model, there can be several billion of them. When you chat with a chatbot, you are using this finished model, and it does not keep learning during the conversation. Some services do remember things about you (a "memory" feature), but they do so by saving separate notes, not by retraining the model.
Training large models is one of the most expensive parts of AI: it can take weeks or months, requiring vast amounts of data, computing power, and electricity. Therefore, only a few companies can build the largest models.
How it works
- Data collection: they compile the training material, i.e., texts, images, audio recordings, or tables. These are often labeled (for example, 'there is a cat in this image'), but with language models, the raw text alone is sufficient.
- Guessing: the model receives an example and attempts to provide the answer, for instance, by guessing the next word in a sentence. At the start, its internal numbers are random, so it almost always makes mistakes.
- Error measurement: a formula calculates how much the guess deviated from the correct answer. This number is the error (loss in English).
- Correction: the system calculates backward from the error how much to adjust which internal number (weight) to reduce the mistake next time.
- Repetition and verification: this loop runs countless times, even millions of times for large models. During and at the end, the model is tested on examples it has not seen before. This reveals whether it truly learned or merely memorized.
An everyday example
Your email spam filter recognizes unsolicited messages because it was trained on millions of emails previously labeled as 'spam' or 'not spam'. When you mark an email as spam yourself, you typically provide a new training example for a future training round.
Who is affected
A common misconception
Limits and risks
- The model only knows what was included in its training data: it has no inherent knowledge of events after training ended, unless provided with a search tool or updated documents.
- If the training data is incorrect, one-sided, or biased, the model learns this too and confidently passes it on.
- Training is not exact storage: the model records patterns, not facts, so it may give plausible but false answers.
- Training large models consumes vast amounts of electricity, water, and money, and the origin of the training data is often opaque.
Similar, but not the same
- inference – Training is the learning phase, while inference is when the finished model answers your question and no longer changes.
- fine-tuning – Fine-tuning is the shorter, targeted further training of an already trained model for a narrower task, not training from scratch.
- Prompting – A prompt guides the model only within that conversation and does not overwrite its internal parameters, whereas training shapes the model itself.
Related concepts
pre-training, fine-tuning, supervised learning, reinforcement learning, self-supervised learning
training data, inference, overfitting, neural network, model weights, deep learning
A brief history
Frank Rosenblatt introduced the perceptron in 1958, one of the first machines that learned from examples. Backpropagation, the basis of modern training, was already described in the 1970s (Seppo Linnainmaa, Paul Werbos). It was widely popularized by David Rumelhart, Geoffrey Hinton, and Ronald Williams in their 1986 study.
Where things stand
By the end of 2026, training remains the foundation of today's machine learning-based AI systems: large language models are trained in massive data centers at enormous cost. Since August 2025, the EU AI Act has required providers of general-purpose models to publish a summary of the content used for training.
In the news
- Cainiao opens its global warehouse network for training embodied AINov 5, 2026 · Ipar
- New standard proposal would simplify how publishers opt out of AI trainingNov 4, 2026 · Marketing
- LG AI Research tool checks copyright risk in training data 45 times fasterNov 4, 2026 · Jog
- South Korea launches AI data factory with 12 bipedal humanoid robotsNov 3, 2026 · Ipar
- Fear, lack of training and limited decision-making power slow workplace AI adoption in HungaryNov 2, 2026 · Work & HR
- White-collar workers quit careers over AI fears or seek 'AI-proof' jobsNov 2, 2026 · Work & HR
- Getting employees to embrace AI takes more than training, reports sayNov 2, 2026 · Work & HR
- Samsung: 95% of students use AI, but few get formal training; parents struggle to adviseNov 2, 2026 · Education & Family
Also known as
training · training · model training · training · training · training · model training · AI training
Sources
- Rumelhart, Hinton, Williams: Learning representations by back-propagating errors (Nature, 1986)
- Wikipedia: Training, validation, and test data sets
This entry was machine-edited and has undergone machine expert review; the “In the news” section updates automatically from Agent Age stories.