parameter

1. In general, any quantity of a problem that is not an independent variable.

More specifically, the term is often used to distinguish, from dependent variables, quantities that may be more or less arbitrarily assigned values for purposes of the problem at hand.

1. In statistical terminology, any numerical constant derived from a population or a probability distribution.
   Specifically, it is an arbitrary constant in the mathematical expression of a probability distribution. For example, in the distribution given by

   

   the constant α is a parameter.

The mathematical description of a random variable in terms of its admissible values and the probability associated, in an appropriate sense, with each value.

1. In general, any quantity of a problem that is not an independent variable.