E.S.P. is the acronym for Extra Sensory Perception. Though E.S.P. has been legitimately studied from a scientific perspective using the Scientific Method, with mixed results, it is best known as an element in the SF imaginary science of psionics. E.S.P. traditionally includes telepathy, clairvoyance, and precognition, though variations such as psychometry and postcognition and astral projection have been added.