My 5 year old came to the dinner table, and calmly announced, "There is no Santa." I was puzzled because just couple of days ago he had taken his Christmas gift from Santa (though now that I think about it, he was not totally thrilled). So I asked why he thought so. He said, "Well, for Christmas I only got the gifts I told you about; I had gone to bed and told Santa himself what I wanted without telling you to see if he is real, and none of those came through - and I was a good boy all year!"
To be sure, I asked him, "But you saw Santa at the mall?" He laughed as hard as could be, then pointed out to me, "They are people in costumes!"
-- Wen Gong
A 5-year-old independently devised hypothesis testing. There is hope for this species.
Now we just need to teach him about estimating the probability that Santa looked at the full range of requests and decided to fulfill a subset that had only been told to the parents.
Rules: