# Sufficiency

> Source: https://sukruyusufkaya.com/en/glossary/yeterlilik
> Updated: 2026-05-13T20:58:52.314Z
> Type: glossary
> Category: matematik-istatistik-optimizasyon
**TLDR:** The property of a statistic containing all relevant information in the data about a parameter.

<p>Sufficiency means that a statistic captures all the relevant information in the data about a parameter. If a statistic is sufficient, the remaining raw data adds no further information about that parameter. This concept is important for understanding statistical efficiency, modeling simplicity, and the power of summary statistics. It shows that not all summaries are equally valuable: some lose information, while others preserve nearly everything important. For that reason, sufficiency is the theoretical answer to the question: “Which summary is actually enough?”</p>