hyun_seoul said:

Start from the measurement rather than the conclusion.

Coming at hyun_seoul’s question from a different direction. Order of operations matters more than any single choice here: establish a baseline, change one thing, wait long enough for it to express itself, then measure again under the same conditions.

Ask again with the specifics and you will get a better answer than this one.

Adding the numbers, since they settle part of this. Say what you would expect to see if you were wrong, before you look. It is a small discipline and it changes what you notice.

Following on from hyun_seoul — and this may be the naive question:

How would you tell the difference between that and the alternative explanation?

TrialTracker_MD said:

Say what you would expect to see if you were wrong, before you look.

Pushing back on TrialTracker_MD here. The objection nobody has made: this only works if the measurement is doing what we assume it is doing, and that assumption has not been tested here.

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

TrialTracker_MD said:

Say what you would expect to see if you were wrong, before you look.

Correct as far as it goes. The part it does not cover is what to do when the honest answer is "not enough data", which is more often than anyone likes.

I would rather be corrected than agreed with, if it comes to it.