# What is the difference between a parametric test and non-parametric tests? [duplicate]

Please explain the difference between a parametric and a non-parametric test.

Do all data mining techniques come under the non-parametric category?

Note that in several situations you can choose between one or another. For instance after calculating the Spearman's rank correlation coefficient on a given dataset, you can estimate its significance using either the fact that you can construct a variable $t$ that follows the student's t distribution and estimate its significance from it, or using a simple permutation test to evaluate the null hypothesis.