&gt; Some experimenters at Twitter proposed running A&#x2F;A&#x2F;B instead of A&#x2F;B tests, to reduce the false positive rate due to “biased” buckets. An A&#x2F;A&#x2F;B test is one in which in addition to the provided control (A1), an experimenter would add another control group (A2) to their experiment.<p>I wonder what intuitions drove that suggestion? Would they be even happier with 3 buckets (each a third of the size)? With 4 (quarters)? 5 (fifths)? ..._n_ buckets, 1 for each sample? At what point did those experimenters think it would stop being an improvement over a single control group?