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**Randomization** is the process of making something random; in various contexts this involves, for example:

- generating a random permutation of a sequence (such as when shuffling cards);
- selecting a random sample of a population (important in statistical sampling);
- allocating experimental units via random assignment to a treatment or control condition;
- generating random numbers (see Random number generation); or
- transforming a data stream (such as when using a scrambler in telecommunications).

Randomization is *not* haphazard. Instead, 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 probability distributions. For example, a random sample of individuals from a population refers to a sample where every individual has a known probability of being sampled. This would be contrasted with nonprobability sampling where arbitrary individuals are selected.