555. One-Sided vs Two-Sided Tests Post-Hoc
hard
A two-sided A/B test is converted to a one-sided test after observing that the treatment is outperforming control. The team claims this is valid since the direction is now known. Why is this incorrect?
A two-sided A/B test is converted to a one-sided test after observing that the treatment is outperforming control. The team claims this is valid since the direction is now known. Why is this incorrect?