Randomness

Randomness means different things in various fields. Commonly, it means lack of pattern or predictability in events.
The Oxford English Dictionary defines "random" as "Having no definite aim orpurpose; not sent or guided in a particular direction; made, done, occurring, etc., without method or conscious choice; haphazard." This concept of randomness suggests a non-order or non-coherence in asequence of symbols or steps, such that there is no intelligible pattern or combination.
Applied usage in science, mathematics and statistics recognizes a lack of predictability when referring torandomness, but admits regularities in the occurrences of events whose outcomes are not certain. For example, when throwing two dice and counting the total, we can say that a sum of 7 will randomlyoccur twice as often as 4. This view, where randomness simply refers to situations where the certainty of the outcome is at issue, applies to concepts of chance, probability, and information entropy. Inthese situations, randomness implies a measure of uncertainty, and notions of haphazardness are irrelevant.
The fields of mathematics, probability, and statistics use formal definitions ofrandomness. In statistics, a random variable is an assignment of a numerical value to each possible outcome of an event space. This association facilitates the identification and the calculation ofprobabilities of the events. A random process is a sequence of random variables describing a process whose outcomes do not follow a deterministic pattern, but follow an evolution described by probabilitydistributions. These and other constructs are extremely useful in the probability calculus.
Randomness is often used in statistics to signify well-defined statistical properties, such as a lack of biasor correlation. Monte Carlo methods, which rely on random input, are important techniques in science, as, for instance, in computational science.[1]
Random selection is a method of selecting items...