Both are right: the two camps posit completely different things.<p>Halvers stipulate a single experiment. Thirders stipulate infinite experiments.<p>It is pretty straightforward math to show these are not inconsistent, and there are even options in between.  <a href="https:&#x2F;&#x2F;stats.stackexchange.com&#x2F;questions&#x2F;41208&#x2F;the-sleeping-beauty-paradox&#x2F;169582#169582" rel="nofollow">https:&#x2F;&#x2F;stats.stackexchange.com&#x2F;questions&#x2F;41208&#x2F;the-sleeping...</a>