This question has been asked virtually the same in this post: Regression Slope and a Bilateral Test

However, I still don't get my head around why when I have a clear hypothesis of a positive relationship between my covariate of interest and the outcome in mind I should "waste" the power of testing whether the relationship could be negative. This is particularly strange to me in the case of experiments where the extra needed power implies having to spend more ressources to collect additional data. Does anybody have an opinion on this or knows statistical literature to read up on?


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.