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  2. Stratified sampling - Wikipedia

    en.wikipedia.org/wiki/Stratified_sampling

    Stratified sampling. In statistics, stratified sampling is a method of sampling from a population which can be partitioned into subpopulations. In statistical surveys, when subpopulations within an overall population vary, it could be advantageous to sample each subpopulation (stratum) independently.

  3. Stratified randomization - Wikipedia

    en.wikipedia.org/wiki/Stratified_randomization

    Graphic breakdown of stratified random sampling. In statistics, stratified randomization is a method of sampling which first stratifies the whole study population into subgroups with same attributes or characteristics, known as strata, then followed by simple random sampling from the stratified groups, where each element within the same subgroup are selected unbiasedly during any stage of the ...

  4. Stratification (clinical trials) - Wikipedia

    en.wikipedia.org/wiki/Stratification_(clinical...

    Proportionate stratified sampling involves selecting participants from each stratum in proportions that match the general population. [1] This method can be used to improve the sample's representation of the population, by ensuring that characteristics (and their proportions) of the study sample reflect the characteristics of the population.

  5. Importance sampling - Wikipedia

    en.wikipedia.org/wiki/Importance_sampling

    The basic idea of importance sampling is to sample the states from a different distribution to lower the variance of the estimation of E [X;P], or when sampling from P is difficult. This is accomplished by first choosing a random variable such that E [L; P] = 1 and that P - almost everywhere . With the variable L we define a probability that ...

  6. Monte Carlo integration - Wikipedia

    en.wikipedia.org/wiki/Monte_Carlo_integration

    Importance sampling provides a very important tool to perform Monte-Carlo integration. [ 3 ] [ 8 ] The main result of importance sampling to this method is that the uniform sampling of x ¯ {\displaystyle {\overline {\mathbf {x} }}} is a particular case of a more generic choice, on which the samples are drawn from any distribution p ( x ...

  7. Variance reduction - Wikipedia

    en.wikipedia.org/wiki/Variance_reduction

    importance sampling; stratified sampling; moment matching; conditional Monte Carlo; and quasi random variables (in Quasi-Monte Carlo method) For simulation with black-box models subset simulation and line sampling can also be used. Under these headings are a variety of specialized techniques; for example, particle transport simulations make ...

  8. Monte Carlo method - Wikipedia

    en.wikipedia.org/wiki/Monte_Carlo_method

    The approximation of a normal distribution with a Monte Carlo method. Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deterministic in principle.

  9. Sample size determination - Wikipedia

    en.wikipedia.org/wiki/Sample_size_determination

    Sample size determination or estimation is the act of choosing the number of observations or replicates to include in a statistical sample. The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample. In practice, the sample size used in a study is usually determined ...