Randomization Information
Randomization is used in statistics and in gambling.
Statistics
Randomization is a core principle in statistical theory, whose importance was emphasized by Charles S. Peirce in "Illustrations of the Logic of Science" (1877–1878) and "A Theory of Probable Inference" (1883). Randomization-based inference is especially important in experimental design and in survey sampling.
Randomized experiments
Main article: Randomized experiment Main article: Randomized controlled trialIn the statistical theory of design of experiments, randomization involves randomly allocating the experimental units across the treatment groups. For example, if an experiment compares a new drug against a standard drug, then the patients should be allocated to either the new drug or to the standard drug control using randomization.
Randomized experimentation is not haphazard. Randomization reduces bias by equalising so-called factors ( independent variables) that have not been accounted for in the experimental design.
Survey sampling
Survey sampling uses randomization, following the criticisms of previous "representative methods" by Jerzy Neyman in his 1922 report to the International Statistical Institute.
Resampling
Main article: Resampling (statistics)Some important methods of statistical inference use resampling from the observed data. Multiple alternative versions of the data-set that "might have been observed" are created by randomization of the original data-set, the only one observed. The variation of statistics calculated for these alternative data-sets is a guide to the uncertainty of statistics estimated from the original data.
Gambling
Randomization is used extensively in the field of gambling (or generally being random[clarification needed]). Because poor randomization may allow a skilled gambler to take advantage, much research has been devoted to effective randomization. A classic example of randomizing is shuffling playing cards.
- See also: Applications of randomness
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 samples and random permutations can be reduced to simply selecting random numbers, random number generation methods are now most commonly used, both hardware random number generators and pseudo-random number generators.
Non-algorithmic randomization methods include:
- Casting yarrow stalks (for the I Ching)
- Throwing dice
- Drawing straws
- Shuffling cards
- Roulette wheels
- Drawing pieces of paper or balls from a bag
- "Lottery machines"
- Observing atomic decay using a radiation counter
See also
References
External links
- RQube - Generate quasi-random stimulus sequences for experimental designs
- RandList - Randomization List Generator
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Categories: Randomness | Experimental design
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Alternative forms
- randomisation (UK)
- The process of making random.