I just realized something.

Carl (and I) think about A/B demand testing from the point of view of trying to teach newbies to use the test, adjust with small doses, test again method ("the TATA method"? ) . . . AND keeping the NUMBER of things tested and taught to a minimum. If a newbie follows the TATA approach, they'll never (or almost never) need the A/B test.

Some of this comes from my background, controlling pH in commercial pools with acid feed, rather than slugged doses.

Evan, you have worked a lot with pool store walk-ins, where you are FORCED to use a large 'fire and forget' doses, because you have no idea if they'll come back. In THAT environment, A/B testing would be almost essential.

And of course, Richard instinctively approaches pool testing from the "how can I acquire the greatest possible amount of analytical information about my pool's water"? Obviously, A/B testing would be a component in that.

So I think what's happened here -- in part -- is we were all speaking from different perspectives, without noticing it. So, now I'm trying to 'notice it'.