[sparsevector]

The problem is that standard statistical tests have two outcomes: (1) "reject the null hypothesis" or (2) "failure to reject the null hypothesis". Moreover in the most common statistical tests the null hypothesis amounts to something like "the two samples were drawn from the same distribution" so if you fail to find a significant difference you haven't shown they're the same, you've just failed to show they're different. If what you want to do is show that they're nearly the same, you can design a statistical test where the null hypothesis is instead something of the sort "these two samples were drawn from distributions that differ by > X amount" so rejecting the null hypothesis shows they differ by <= X.