# Information Gain

> Source: https://sukruyusufkaya.com/en/glossary/bilgi-kazanci
> Updated: 2026-05-13T21:01:31.310Z
> Type: glossary
> Category: matematik-istatistik-optimizasyon
**TLDR:** An information-theoretic concept that measures how much uncertainty a feature reduces, especially in decision trees.

<p>Information gain measures how much a variable reduces uncertainty about the target variable. For this reason, it is widely used in decision trees to choose which feature should be selected for a split. It is computed through differences in entropy and indicates which feature separates the data most meaningfully. It is also valuable in feature selection and explanatory analysis. Information gain is the information-theoretic answer to the question: “Which variable actually carries useful information?”</p>