Is the Selection Effect Getting Right?

i like to think of objections as tools for test ing and clarifying arguments. There can be sometimes a selection effect worry where, ah, you are getting data that a is confirming a hypothesis, but you couldn't get it in the first place. So i find it very helpful to think of them as tools to clarify. Ah, well, so which primis right? Does it target the argument? I mean, what robin was saying was right, because you still have the primist ak.