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Re:Everything Is Correlated by ivan_ah on Thursday May 02, 2019 @01:22AM (#19804977)
Agree that NHST using simple null hypothesis of the form

   H0:  μ = 0
doesn't provide much value. H0 is never true, and the conclusion of "rejecting H0" based on a p-value is therefore not super profound. Also "rejecting H0" conclusion doesn't really tells anything about the alternative hypothesis HA (not even considered when computing p-value, since p-value is under H0). Dichotomies in general are bad, but NHST with point H0 is useless!

However a composite hypothesis setup of the form

   H0:  μ ≤ 0
   HA:  μ > 0
is probabilistically sound (in as much as some journal requires you to report a p-values). Much better to report effect size estimate and/or CI.
Re:Everything Is Correlated by nonbel on Thursday May 02, 2019 @11:10AM (#19808674)
That still gives 50-50 odds with sufficient sample size, not much of a test of the research hypothesis (since many alternatives will predict the same direction). It is better than 100% chance of rejection though.
Re:Everything Is Correlated by mjfl on Thursday May 02, 2019 @04:38AM (#19805886)
Couldn't you make an argument that the point H0 has use when you are testing whether two populations are identical? i.e. it's probably true that \mu is very close to 0 if it is the difference in heights of men from Nebraska vs men from Iowa.
Re:Everything Is Correlated by rwj on Thursday May 02, 2019 @10:09AM (#19808054)
You've kind of hit the point with the second half of your comment. Two populations are virtually never identical, so you don't need any statistics to answer the question. A more reasonable question is whether or not you have the statistical power (i.e. measurement precision) to see the difference, and whether the difference is big enough to matter.