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What is Confusion Matrix

GlossaryMachine Learning

A table that shows which classes the model recognized correctly and where it mixed up the answers.

Definition

Confusion Matrix is a table that shows which classes the model recognized correctly and where it got the answers wrong. Simply put, this concept helps train models, compare approaches, and reduce the risk of errors on new data. In practice, it helps to understand what capabilities the tool actually has, what data it will need, and what limitations are worth checking before implementation.

Example

For the medical model, false alarms and missed cases are counted separately because the cost of errors is different.

Why it matters

The error matrix makes classification quality clearer than overall accuracy alone. This helps you choose AI tools not by big promises, but by how they work in a real problem.

How it works

First, the problem is translated into data and metrics, then the model is trained, tested on a separate sample, and compared with alternatives. In the case of the term “Error Matrix”, it is important to look separately at the data, quality criteria and application conditions.

Where it is used

  • Used in training, testing and tuning models, in automatic selection of parameters, forecasting, classification and recommendation systems.

Limitations

The main limitation is the dependence on data, metrics and verification conditions. A good result on a test does not always mean reliable performance in a real product.