In the theory of probability and statistics, a Bernoulli trial is an experiment whose outcome is random and can be either of two possible outcomes, "success" and "failure".

In practice it refers to a single experiment which can have one of two possible outcomes. These events can be phrased into "yes or no" questions:

Therefore success and failure are labels for outcomes, and should not be construed literally. Examples of Bernoulli trials include

Independent repeated trials of an experiment with two outcomes only are called Bernoulli trials. Call one of the outcomes "success" and the other outcome "failure". Let Failed to parse (Missing texvc executable; please see math/README to configure.): p

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Random variables describing Bernoulli trials are often encoded using the convention that 1 = "success", 0 = "failure". Then, the probability distribution of such a random variable (termed a Bernoulli distribution) is given by

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Closely related to a Bernoulli trial is a binomial experiment, which consists of a fixed number Failed to parse (Missing texvc executable; please see math/README to configure.): n