Nonparametric Tests

Statistical tests that don't require the distribution to have certain parameters such as a normal distribution with parameters μ and σ. Since they don't require these parameters typical for normal distributions, these tests can be very powerful when testing non-normal distributions.
Related StatStuff Video: 
   -Section 6-Analyze Phase, Lesson #19 - Hypothesis Testing: Central Tend. - Non-Normal (Nonparametric Tests)