Omega squared (ω2) is a descriptive statistic used to quantify the strength of the relationship between a qualitative explanatory (independent or grouping) variable and a quantitative response (dependent or outcome) variable. The relationship is interpreted in terms of the proportion of variation in the response variable that is associated with the explanatory variable. As a proportion, it can have values between 0 and 1, with 0 indicating no relationship and 1 indicating that all of the variation in the response variable is attributed to the explanatory variable. Omega squared is used as an effect-size index to judge the meaningfulness of the observed relationship identified using the analysis of variance F test. It can supplement the results of hypothesis tests comparing two or more population means. ...