In statistics, the<unk>  tests the null hypothesis that a sample x1, ..., xn came from a normally distributed population. It was published in 1965 by Samuel<unk>  and Martin<unk> .
The test statistic is
where
x(i) (with parentheses enclosing the subscript index i) is the ith order statistic, i.e., the ith-smallest number in the sample;
x
¯
=
(
x
1
+
⋯
+
x
n
)
/
n
{\displaystyle {\overline {x}}=(x_{1}+\cdots +x_{n})/n\,}
 is the sample mean;
the constants ai are given by
The user may reject the null hypothesis if W is too small.
Shapiro-Wilk test
Brown-Forsythe test
Bartlett's test
Kendall tau rank correlation coefficient
Analysis of rhythmic variance
Cohen's kappa
ANOVA-simultaneous component analysis
Wilcoxon signed-rank test