I just read the best paper I've seen yet this year, Sam Zhang's work on confusion between inferential uncertainty and outcome variability.

In the context of a trial or experiment, inferential uncertainty refers to our statistical confidence that two groups are different. Outcome variability refers to how much variation there is in individual outcomes within a single group.

IMO confusion about this is ubiquitous in biomedical science.

Here's the paper: https://osf.io/preprints/socarxiv/5tcgs/