# Blog - Entropy

Entropy is generally thought of as disorder. The formula for entropy is given by: $H(X) = - \sum_{i=1}^{n}P(x_i)\log P(x_i)$. If we consider $X = \text{Bernoulli}(p)$, we can clearly see that entropy is highest when we cannot easily guess what value the random variable will take (when $p=.5$). Entropy is lowest at 0 when we know the value that $X$ will always take ($p = 0$ or $p=.5$).

#### Citations

• https://en.wikipedia.org/wiki/Entropy_(information_theory)
• https://en.wikipedia.org/wiki/Bernoulli_distribution