NicoleRaleigh said:

Practical: whatever you change, write down the date and the reason.

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.

NicoleRaleigh said:

Practical: whatever you change, write down the date and the reason.

This answered a question I did not know how to ask. I will report back once I have actually tried it.

Adding the clinical framing, because it changes how the question reads. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.

Happy to go further on any of that.

jim_asheville said:

Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…

Second this. Nothing to add that would improve it.

jim_asheville said:

Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…

Adding the part of the answer the thread has not reached. Most of what circulates confidently in this community traces back to one summary of one study, and the qualifier was dropped somewhere in the third retelling.