Stat Questions

A running column: a real statistics question pulled from the wild - a forum thread, a comment section, a corridor conversation - worked end to end the way a biostatistician would. The trap is the same whether it's a hobbyist asking why Tuesdays feel lucky, or a subgroup result buried in a clinical trial. Try to answer before we do.

Multiple comparisons · the look-everywhere effect · from r/AskStatistics

Is that lucky streak real - or did you just look hard enough?

Someone tracks their outcomes by hour, weekday and day of the month, and asks when a lucky pattern becomes worth taking seriously. The honest answer overturns the question - with a live simulator, the aspirin-and-astrology trial, and a 5-step plan to tell signal from noise.

Read the case