The Beta distribution is a continuous probability distribution often used to model the uncertainty about the probability of success of an experiment.

## How the distribution is used

The Beta distribution can be used to analyze probabilistic experiments that have only two possible outcomes:

- success, with probability χ;
- failure, with probability 1 – χ .

These experiments are called Bernoulli experiments.

### Data collection

Now, suppose that:

- we perform η independent repetitions of the experiment;
- we observe κ successes and n — κ failures.

The number of successes obtained in η independent repetitions of a random experiment having probability of success χ is a binomial random variable with parameters χ and η.