Statistical parameter

Quantity that indexes a parametrized family of probability distributions

In statistics, as opposed to its general use in mathematics, a parameter is any quantity of a statistical population that summarizes or describes an aspect of the population, such as a mean or a standard deviation. If a population exactly follows a known and defined distribution, for example the normal distribution, then a small set of parameters can be measured which provide a comprehensive description of the population, and can be considered to define a probability distribution for the purposes of extracting samples from this population.

This keyword could refer to multiple things. Here are some suggestions: