hans_munich said:

Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the…

There is a second half to this that has not been said yet. It helps to say which part of this you are uncertain about. A precise question gets a precise answer; a general one gets everybody’s favourite anecdote.

Old thread, but it comes up first when you search for this, so it is worth updating. One practical note: write down what you did and when, before you need it. Reconstructing a timeline from memory three months later is how people end up unable to answer the one question that would have resolved it.

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

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

What would you measure differently if you were starting again?

PedsEndoPhilly said:

One practical note: write down what you did and when, before you need it.

I am going to disagree with the direction of travel here. The thread has converged on the tidiest answer rather than the best-supported one, and those are not the same thing.

PedsEndoPhilly said:

One practical note: write down what you did and when, before you need it.

Agreed, and the size of the effect matters as much as its existence. Something real and small gets treated here as though it were real and decisive.

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