Published On: 26/06/2010|Categories: 2008–2012, Vol.31 (2), Vol.31 (2010)|

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Tests of the equality of variances are sometimes used on their own to compare variability across groups of experimental or non-experimental conditions but they are most often used alongside other methods to support assumptions made about variances. A new nonparametric test of equality of variances is described and compared to current ‘gold standard’ method, the median-based Levene test, in a computer simulation study. The simulation results show that when sampling from either symmetric or skewed population distributions both the median based and nonparametric Levene tests maintain their nominal Type I error rate; however, when one is sampling from skewed population distributions the nonparametric test has more statistical power.

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