Editing Randomization (section)

==Techniques==
Although historically "manual" randomization techniques (such as shuffling cards, drawing pieces of paper from a bag, spinning a [[roulette]] wheel) were common, nowadays automated techniques are mostly used. As both selecting [[random sample]]s and [[random permutation]]s can be reduced to simply selecting random numbers, [[random number generation]] methods are now most commonly used, both [[hardware random number generator]]s and [[pseudo-random number generator]]s.

===Optimization===
Randomization is used in optimization to alleviate the computational burden associated to robust control techniques: a sample of values of the uncertainty parameters is randomly drawn and robustness is enforced for these values only. This approach has gained popularity by the introduction of rigorous theories that permit one to have control on the probabilistic level of robustness, see [[scenario optimization]]. 

Common randomization methods including

* Simple randomization ([[coin flipping]], [[Drawing lots (decision making)|drawing lots]] and [[Random number generation|random number method]]）<ref name=":6" />
* [[Stratified randomization]] ([[stratified sampling]] and stratified allocation)<ref name=":6" />
* Block randomization<ref name=":6" />
* Systematic randomization
* Cluster randomization
* [[Multistage sampling]]
* [[Quasi-randomization]]
* Covariate Adaptive Randomization<ref name=":6" />