Post #2292059

My own two cents (that may diverge from common practice): Option 1 is a valid and probably preferable approach. With a preregistered directed hypothesis, this is a more severe test of the hypothesis (but would have been better if the one-tailed testing was preregistered). Option 2 may be valid, if the preregistration doesn't make it sufficiently clear that the hypothesis was directional. Option 3 I would say is not a valid approach. Two-tailed testing should be used to test whether there is ANY association between variables (positive or negative). A significant effect in one of the tested direction should thus not be used to argue against a directional hypothesis (which you are not testing).