Adjective

random (comparative more random, superlative most random)

Positive random

Comparative more random

Superlative most random

1. All outcomes being unpredictable and, in the ideal case, equally probable; resulting from such selection; lacking statistical correlation.

   The flip of a fair coin is purely random.

   The newspaper conducted a random sample of five hundred American teenagers.

   The results of the field survey look random by several different measures.

2. (mathematics) Of or relating to probability distribution.

   A toss of loaded dice is still random, though biased.

3. (computing) Pseudorandom in contrast to truly random; mimicking the result of random selection.

   The rand function generates a random number from a seed.

4. (colloquial) Representative and undistinguished; typical and average.

   A random American off the street couldn't tell the difference.

5. (colloquial) Apropos of nothing; lacking context; unexpected; having apparent lack of plan, cause, or reason.

   That was a completely random comment.

   The teacher's bartending story was interesting, but random.

   The narrative takes a random course.

Randomness is a concept with somewhat disparate meanings in several fields. It also has a common meaning which has a loose connection with some of those more definite meanings.

Closely connected with the concept of entropy, randomness implies a of lack of predictability. Randomness, as defined by Aristotle, is the situation when a choice is to be made which has no logical component by which to determine or make the choice (see Buridan's ass). More recently, and more formally, a random process is a repeating process whose outcomes follow no describable deterministic pattern, but follow a probability distribution, such that the relative probability of the occurrence of each outcome can be approximated or calculated. For instance, the rolling of a six-sided die in neutral conditions may be said to produce random results in that one cannot compute before a roll what digit will be landed on, but the probability of landing on any of the six rollable digits can be calculated because of the finite cardinality of the set of possible outcomes.

The term is often used in statistics to signify well-defined statistical properties, such as a lack of bias or correlation. Monte Carlo Methods, which rely on random input, are important techniques in science, as, for instance, computational science. Random selection is an official method to resolve tied elections in some jurisdictions and is even an ancient method of divination, as in tarot, the I Ching, and bibliomancy. Its use in politics is very old, as office holders in Ancient Athens were chosen by lot, there being no voting.