Normality Tests

A common application for distribution fitting procedures is when you want to verify the assumption of normality before using some parametric test (see Basic Statistics and Nonparametric Statistics). A variety of statistics for testing normality are available including the Kolmogorov-Smirnov test for normality, the Shapiro-Wilk W test, and the Lilliefors test. Additionally, you can review probability plots and normal probability plots to assess whether the data are accurately modeled by a normal distribution.