DictionaryentropyInformation uncertainty
noun

entropy

A measure of uncertainty in the possible outcomes of an information source.

The source's entropy measured uncertainty in its output.

Etymology

Entropy was coined around a Greek word for transformation. Information theory borrowed the term for uncertainty, using a mathematical form closely related to the physical measure.

More examples

  • A predictable message had lower entropy than a random one.
  • The coding scheme approached the source's entropy limit.
  • They calculated entropy from the outcome probabilities.

Forms

entropy

Similar words

uncertainty
Uncertainty is general; information entropy quantifies it from outcome probabilities.
redundancy
Redundancy repeats predictable information; higher predictability generally lowers entropy per symbol.