in connection with the anthropic principle. Variations Extreme Sleeping Beauty This differs from the original in that there are one million and one wakings if tails comes up. It was formulated by Nick Bostrom. Sailor's Child problem The Sailor's Child problem, introduced by Radford M. Neal, is somewhat similar. It involves a sailor who regularly sails between ports. In one port there is a woman who wants to have a child with him, across the sea there is another woman who also wants to have a child with him. The sailor cannot decide if he will have one or two children, so he will leave it up to a coin toss. If Heads, he will have one child, and if Tails, two children. But if the coin lands on Heads, which woman would have his child? He would decide this by looking at The Sailor's Guide to Ports and the woman in the port that appears first would be the woman that he has a child with. You are his child. You do not have a copy of The Sailor's Guide to Ports. What is the probability that you are his only child, thus the coin landed on Heads (assume a fair coin)? See also Doomsday argument Bayesian probability Monty Hall problem Boy or Girl paradox References Other works discussing the Sleeping Beauty problem Colombo, M., Lai, J. & Crupi, V. Sleeping Beauty Goes to the Lab: The Psychology of Self-Locating Evidence. Rev.Phil.Psych. 10, 173–185 (2019). https://doi.org/10.1007/s13164-018-0381-8 Neal, R. (2006). Puzzles of Anthropic Reasoning Resolved Using Full Non-indexical Conditioning, preprint Titelbaum, M. (2013). Quitting Certainties, 210–229, 233–237, 241–249, 250, 276–277 External links Terry Horgan: Sleeping Beauty Awakened: New Odds at the Dawn of the New Day (review paper with references) Anthropic Preprint Archive: The Sleeping Beauty Problem: An archive of papers on this problem Phil Papers Entry on Sleeping Beauty (a complete bibliography of papers on the problem) Twoplustwo thread discussing the sleeping beauty problem in depth Probability theory paradoxes Puzzles Probability problems Epistemology