Hello! There are many ELI about statistical power, but I didn’t see one asking quite what I’m wondering about – the basic question is:
If power is related to the number of people required to detect a difference between groups, is it important that a trial was underpowered if it found a statistically significant difference between groups?
It seems like maybe not(?) since at that point you can no longer have made a Type 2 error, only Type 1? But being underpowered is often discussed, so I’m curious why.