Version: v1, Published online: 1998

Retrieved July 15, 2020, from https://www.rep.routledge.com/articles/thematic/randomness/v-1

## Article Summary

The fundamental intuition underlying randomness is the absence of order or pattern. To cash out this intuition philosophers and scientists employ five approaches to randomness.

(1) Randomness as the output of a chance process. Thus an event is *random* if it is the output of a chance process. Moreover, a sequence of events constitutes a *random sample* if all events in the sequence derive from a single chance process and no event in the sequence is influenced by the others.

(2) Randomness as mimicking chance. Statisticians frequently wish to obtain a random sample (in the sense of (1)) according to some specified probability distribution. Unfortunately, a chance process corresponding to this probability distribution may be hard to come by. In this case a statistician may employ a computer simulation to mimic the desired chance process (for example, a random number generator). Randomness *qua* mimicking chance is also known as *pseudo-randomness*.

(3) Randomness via mixing. Consider the following situation: particles are concentrated in some corner of a fluid; forces act on the fluid so that eventually the particles become thoroughly mixed throughout the fluid, reaching an equilibrium state. Here randomness is identified with the equilibrium state reached via mixing.

(4) Randomness as a measure of computational complexity. Computers are ideally suited for generating bit strings. The length of the shortest program that generates a given bit string, as well as the minimum time it takes for a program to generate the string, both assign measures of complexity to the strings. The higher the complexity, the more random the string.

(5) Randomness as pattern-breaking. Given a specified collection of patterns, an object is random if it breaks all the patterns in the collection. If, on the other hand, it fits at least one of the patterns in the collection, then it fails to be random.

Dembski, William A.. Randomness, 1998, doi:10.4324/9780415249126-Q087-1. Routledge Encyclopedia of Philosophy, Taylor and Francis, https://www.rep.routledge.com/articles/thematic/randomness/v-1.

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