Changes

==Comparing a quantitative variable between more than two groups==

==Comparing a quantitative variable between more than two groups==

===ANOVA (analysis of variance)===

===F-test===

The F-test is used when comparing the means of two or more quantitative variables, as is the case when conducting an ANOVA (analysis of variance). The basic concept of an ANOVA is that the total variation in a population can be viewed as being comprised of the variation between the groups (i.e. 'explained variation') and variation within the groups (i.e. 'unexplained variation'). The F statistic is based upon the ratio of a measure of the variance between groups (the 'mean square of treatment', MSTR) to a measure of the variance within groups (the 'mean square error', MSE).

===Kruskal-Wallis test===

===Kruskal-Wallis test===