Friedman Test

Friedman test is used to test the difference between treatments across multiple test subjects. Friedman Test is a non-parametric alternative to the parametric Two-Way ANOVA.


$F_R =\dfrac{12}{nk(k+1)}\sum_{j=1}^k R_{\cdot j}^2-3n(k+1)$


  • $k$ is the number of treatments
  • $n$ is the number of blocks
  • $R_{\cdot j}$ is the sum of the ranks for $j^{th}$ treatment

Suggestions and comments will be appreciated.