Level of measurementLevel of measurement or scale of measure is a classification that describes the nature of information within the values assigned to variables. Psychologist Stanley Smith Stevens developed the best-known classification with four levels, or scales, of measurement: nominal, ordinal, interval, and ratio. This framework of distinguishing levels of measurement originated in psychology and has since had a complex history, being adopted and extended in some disciplines and by some scholars, and criticized or rejected by others.
PhenomenonA phenomenon (: phenomena), sometimes spelled phaenomenon, is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which cannot be directly observed. Kant was heavily influenced by Gottfried Wilhelm Leibniz in this part of his philosophy, in which phenomenon and noumenon serve as interrelated technical terms. Far predating this, the ancient Greek Pyrrhonist philosopher Sextus Empiricus also used phenomenon and noumenon as interrelated technical terms.
Charles FortCharles Hoy Fort (August 6, 1874 – May 3, 1932) was an American writer and researcher who specialized in anomalous phenomena. The terms "Fortean" and "Forteana" are sometimes used to characterize various such phenomena. Fort's books sold well and are still in print. His work continues to inspire admirers, who refer to themselves as "Forteans", and has influenced some aspects of science fiction. Fort's collections of scientific anomalies, including The Book of the Damned (1919), influenced numerous science-fiction writers with their skepticism and as sources of ideas.
Unidentified flying objectAn unidentified flying object (UFO), or unidentified aerial (or anomalous) phenomenon (UAP), is any perceived aerial phenomenon that cannot be immediately identified or explained. Upon investigation, most UFOs are identified as known objects or atmospheric phenomena, while a small number remain unexplained. While unusual sightings have been reported in the sky throughout history, UFOs became culturally prominent after World War II, escalating during the Space Age.
PoltergeistIn ghostlore, a poltergeist (ˈpoʊltərˌgaɪst or ˈpɒltərˌgaɪst; German for "rumbling ghost" or "noisy spirit") is a type of ghost or spirit that is responsible for physical disturbances, such as loud noises and objects being moved or destroyed. Most claims or fictional descriptions of poltergeists show them as being capable of pinching, biting, hitting, and tripping people. They are also depicted as capable of the movement or levitation of objects such as furniture and cutlery, or noises such as knocking on doors.