Similarity 532523 222784559 2008-07-01T02:39:32Z Artichoker 4969156 Reverted edits by [[Special:Contributions/Creditowed|Creditowed]] ([[User talk:Creditowed|talk]]) to last version by 128.250.80.15 {{Wiktionary|similarity}} '''Similarity''' is some degree of [[symmetry]] in either [[analogy]] and [[resemblance]] between two or more [[concept]]s or [[physical object|object]]s. The notion of similarity rests either on exact or approximate repetitions of [[pattern]]s in the [[comparison|compared]] items. In the case of approximate repetitions we talk about '''statistical similarity''' as found in a [[fractal]] and its parts. Finding similarities or distinguishing between dissimilarities depends on the faculties of [[pattern recognition]] and [[disambiguation]], respectively. A general method to calculate [[probability]] of an event based on another similar event is called relative [[probability]] <br /> If A, B are different events<br /> Probability of A = P(A)<br /> Then P(B) = P(A) x R where R is the similarity ratio between A,B<br /> If A=B --> R=1<br /> If A<>B --> R=0<br /> ==Specific definitions== Different fields provide differing definitions of similarity: * In [[mathematics]], ** [[Similarity (geometry)]] ** [[Similar matrix|Similar matrices]] * In [[psychology]], [[similarity (psychology)]] * In [[music]], [[Musical similarity]] * In [[chemistry]], [[Chemical similarity]] * In [[engineering]], [[Similitude (model)|similarity or similitude]] describe the geometric, kinematic and dynamic 'likeness' of two (or more) systems. * In [[computational linguistics]], [[semantic similarity]] * In [[philosophy]], similarity is defined as sharing [[property|properties]] or [[characteristic]] traits. The sky is similar to the sea, for example, because the sky and the sea both share the property of being blue. This definition has some interesting consequences. First, it follows that resemblance is reflexive, since everything shares its own properties. Second, it follows that resemblance is symmetric, since if x shares properties with y then y shares those same properties with x. Third, qualitative identity turns out to be a limiting case of resemblance, since qualitative identity is defined as sharing all rather than some properties. ==See also== [[difference]], [[sameness]], [[equality]] {{disambig}} [[de:Ähnlichkeit]] [[fr:similitude]]