ScottKnott ESD test

ScottKnott ESD (Extreme Studentized Deviate) test is a post-hoc statistical test used to compare the means of multiple groups after performing an analysis of variance (ANOVA). The test is designed to identify statistically significant differences between groups and to rank the groups based on their means.

The ScottKnott ESD test uses a stepwise approach to perform pairwise comparisons between groups. It first identifies the group with the largest mean and then partitions the remaining groups into two subgroups based on their mean values. The test then calculates the ESD statistic for each subgroup and selects the subgroup with the largest ESD value. This process is repeated until all the groups have been compared and ranked based on their means.

The ScottKnott ESD test is useful for identifying significant differences between groups that may be missed by other post-hoc tests. It is particularly effective when dealing with large datasets and can handle unbalanced group sizes. However, it should be noted that the test assumes normality and homogeneity of variances, which should be checked before using the test.