One thing that is still open after pat_auckland’s answer:

Was that from a primary source or from a summary of one?

JessicaM_2024 said:

The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the…

This is where I part company with the consensus forming above. Not convinced. The evidence being cited is consistent with the conclusion and also consistent with two other conclusions nobody has ruled out.

JessicaM_2024 said:

The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the…

That holds where the measurement is reliable. Where it is noisy — and a lot of what gets tracked here is noisy — the same reasoning produces confident nonsense.

That is the short version; the long version is somebody else's post.

JessicaM_2024 said:

The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the…

Thank you for spelling out the reasoning rather than just the conclusion.

From the other side of the consultation, briefly. Practical: whatever you change, write down the date and the reason. In three months the reason is what you will have forgotten, and the reason is what makes the record worth having.