What is entropy in probability theory?

Updated May 17, 2026

Short answer

Entropy measures uncertainty in a probability distribution.

Deep explanation

Defined as H(X) = -Σ p(x) log p(x). Higher entropy means more randomness. It is foundational in information theory and machine learning.

Real-world example

Measuring uncertainty in weather prediction.

Common mistakes

  • Confusing entropy with variance.

Follow-up questions

  • What is high entropy?
  • Where is entropy used?

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