Randomization is the process of making something random; this means:

  • 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.
  • 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.

Read more about Randomization:  Techniques