Probability/Probablistic

(with thanks to Bear and J Fawcett, definition constructed December 2003)

Definition: probabilistic Relating to, or governed by, probability. The behaviour of a probabilistic system cannot be predicted exactly but the probability of certain behaviours is known. Such systems may be simulated using pseudo-random numbers. Evolutionary computation uses probabilistic processes to generate new (potential) solutions to a problem. http://www.hyperdictionary.com/computing/probabilistic Definition: probabilistically [adv] by the use of probability theory; "we can calculate the position of the particles probabilistically" http://www.hyperdictionary.com/computing/probabilistically and, of course, the OED entry: probabilistic , a. [f. probabilist: see -istic.] 1. Pertaining to probabilists or probabilism. 1864 Chambers's Encycl. VI. 131/1 In that [R.C.] church his [Liguori's] moral theology,..a modification of the so-called `probabilistic system' of the age immediately before his own, is largely used in the direction of consciences. 2. Pertaining to or expressing probability; subject to or involving chance variations or uncertainties. 1951 Philos. of Sci. XVIII. 216 The recognition of the probabilistic character of environmental cue-object and means-end relationships through replacement of the traditional absolute right-wrong alternatives..by cues or means of lower statistical validity. 1957 N. Chomsky Syntactic Struct. ii. 17 The development of probabilistic models for the use of language (as distinct from the syntactic structure of language) can be quite rewarding. 1965 C. H. Springer et al. Adv. Methods & Models i. 11 Models which are based on the mathematics of statistics and probability, into which we introduce the uncertainties which usually accompany our observations of real events, are called probabilistic models. 1966 C. G. Hempel Philos. Nat. Sci. v. 65 Many important laws and theoretical principles in the natural sciences are of probabilistic character. 1972 Computers & Humanities VII. 17 His lengthier treatment of two stochastic models notes that probabilistic stylistics is somewhat more advanced than deterministic approaches. 1978 Sci. Amer. Feb. 131/3 The strict determinism of classical mechanics is abandoned in the quantum theory and is replaced by a probabilistic interpretation of measurements at the microscopic level. Hence probabi'listically adv., in a probabilistic manner; in terms of probabilities. 1955 Science 11 Nov. 910/1 Not only perception but also thinking and valuing are fruitfully conceived as only in some degree probabilistically valid achievements. 1965 Language XLI. 201 Between the total workings of such a determinate system..and the sound a speaker produces there is a layer of indeterminacy that can only be handled probabilistically. 1975 Nature 17 July 166/2 Equations such as (2) and (3) can provide very simple examples of fully deterministic systems whose dynamics are best described probabilistically. 1978 Sci. Amer. June 99/2 The processes that govern the placing of telephone calls are so complicated that it is more fruitful to view them probabilistically than to do so deterministically.

Probabilisitic is the adjective form for probablism. Probalism, in philosophy, refers to the doctrine introduced by the Skeptics, that certainty is impossible and that probability suffices to govern faith and practice. Probability refers to the quality or fact of being probable. Probable refers to likely to occur or prove true.