Everywhere you look it's all about finding whether you can reject that two samples are different or not.
But how do you interpret it, when you go the "opposite" way around? E.g. I have two values, from experiment and theory that are similar. A Z-test reveals they're only 0.1 sigmas apart.
There's no way that they would be different, but could the wording be turned around so that we could say "we're extremely sure that they're the similar, which validates experiment and theory"?
Is it valid to say, similar to rejection at $p=\alpha$, to accept values as being "similar enough" at $p=1-\alpha$?