Informal "competition" fits in there, too. Working and sparring with people you don't know (at least from a training perspective) both within and outside your own art/style.Not about challenging dogma, although that's a by product of it, in my opinion.
Regarding testing a style's effectiveness, I can think of a few ways to do that. Competition. Working as a professional cop, bouncer, body guard, soldier, or soldier of fortune. Criminal.
Only one of those is practical and accessible for the average person. Can you think of others? I can't. I can think of other ways to train that are great. But training is not testing. One leads to the other.