Lexis ratio

The Lexis ratio, also known as Q, is a ratio used in statistical analysis to evaluate how data compares to a Bernoulli distribution. It is computed as follows:


 * $$\mathrm{L} = \frac{\sigma}{\sigma_B}.$$

Where σ is the variance given from a set of Lexis trials and σB is the variance computed from the expected Bernoulli distribution. Trials where L falls significantly above or below 1 are known as supernormal and subnormal, respectively.

Subnormal trials are particularly of note because they tend to indicate that the data follows a Poisson distribution.