<P> Parametric statistics is a branch of statistics which assumes that sample data comes from a population that follows a probability distribution based on a fixed set of parameters . Most well - known elementary statistical methods are parametric . Conversely a non-parametric model differs precisely in that the parameter set ( or feature set in machine learning ) is not fixed and can increase , or even decrease if new relevant information is collected . </P>
the collection of statistical methods that require assumptions about the population is known as
Parametric statistics