Critical Power-10 minute and 20 minute discrepancy

RChung

It may not. However, in your original suggestion to collect a third point, I didn't see anything that warned that collection protocols are critical. In my field, collecting good data is both hard and expensive so we do everything possible to make sure that the few data we do collect are collected consistently (even if "consistently" doesn't always mean the same thing as "carefully"). In essence, collecting more data is something you do when you're worried about sampling error. However, in a case like this I'd be a lot more concerned about non-sampling error. Consistency of collection means that even if the estimate is biased, you hope that you can make it biased in the same direction each time so you can still detect changes in the estimate. In a numerical estimation sense, the increase from two observations to three does almost nothing to reduce sampling error (you'd probably need an order of magnitude more observations to do anything about that) so you're better off putting that effort into better collection.