The article compares different tests used to check if two sets of numbers have the same amount of variation. One test is based on the difference in the sample variances, while another is a nonparametric test. The researchers found that the nonparametric test, called the R test, is almost as powerful as the parametric test and almost as robust as the nonparametric test. This means the R test is a good choice for checking if two sets of numbers have the same amount of variation, even if the numbers don't follow a normal pattern.