Harry Potter and the Methods of Rationality (HPMOR) is a work of Harry Potterfan fiction by Eliezer Yudkowsky published on FanFiction.Net as a serial from February 28, 2010,[1] to March 14, 2015,[2] totaling 122 chapters and over 660,000 words.[3][4] It adapts the story of Harry Potter to explain complex concepts in cognitive science, philosophy, and the scientific method.[5] Yudkowsky's reimagining supposes that Harry's aunt Petunia Evans married an Oxford professor and homeschooled Harry in science and rational thinking,[2][4] allowing Harry to enter the magical world with ideals from the Age of Enlightenment and an experimental spirit.[6] The fan fiction spans one year, covering Harry's first year in Hogwarts.[7]HPMOR has inspired other works of fan fiction, art, and poetry.[8]