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  2. Simple random sample - Wikipedia

    en.wikipedia.org/wiki/Simple_random_sample

    Using a simple random sample will always lead to an epsem, but not all epsem samples are SRS. For example, if a teacher has a class arranged in 5 rows of 6 columns and she wants to take a random sample of 5 students she might pick one of the 6 columns at random. This would be an epsem sample but not all subsets of 5 pupils are equally likely ...

  3. Design effect - Wikipedia

    en.wikipedia.org/wiki/Design_effect

    For general EPSEM (equal probability sampling) will still be Bernoulli with some parameter , but they may no longer be independent random variables. I.e., knowing that a sample is EPSEM means that it maintains marginally equal probability of selection, but it does not inform us about the joint probability of selection.

  4. Systematic sampling - Wikipedia

    en.wikipedia.org/wiki/Systematic_sampling

    where n is the sample size, and N is the population size. Using this procedure each element in the population has a known and equal probability of selection (also known as epsem). This makes systematic sampling functionally similar to simple random sampling (SRS). However, it is not the same as SRS because not every possible sample of a certain ...

  5. Random variable - Wikipedia

    en.wikipedia.org/wiki/Random_variable

    A random variable (also called random quantity, aleatory variable, or stochastic variable) is a mathematical formalization of a quantity or object which depends on random events. [1] The term 'random variable' in its mathematical definition refers to neither randomness nor variability [2] but instead is a mathematical function in which.

  6. Expander walk sampling - Wikipedia

    en.wikipedia.org/wiki/Expander_walk_sampling

    Sampling from an expander walk is an example of a randomness-efficient sampler. Note that the number of bits used in sampling k {\displaystyle k} independent samples from f {\displaystyle f} is k log ⁡ n {\displaystyle k\log n} , whereas if we sample from an infinite family of constant-degree expanders this costs only log ⁡ n + O ( k ...

  7. Random graph - Wikipedia

    en.wikipedia.org/wiki/Random_graph

    In mathematics, random graph is the general term to refer to probability distributions over graphs. Random graphs may be described simply by a probability distribution, or by a random process which generates them. [1] [2] [3] The theory of random graphs lies at the intersection between graph theory and probability theory.

  8. Random assignment - Wikipedia

    en.wikipedia.org/wiki/Random_assignment

    Random assignment or random placement is an experimental technique for assigning human participants or animal subjects to different groups in an experiment (e.g., a treatment group versus a control group) using randomization, such as by a chance procedure (e.g., flipping a coin) or a random number generator. [1]

  9. Berry–Esseen theorem - Wikipedia

    en.wikipedia.org/wiki/Berry–Esseen_theorem

    In probability theory, the central limit theorem states that, under certain circumstances, the probability distribution of the scaled mean of a random sample converges to a normal distribution as the sample size increases to infinity. Under stronger assumptions, the Berry–Esseen theorem, or Berry–Esseen inequality, gives a more quantitative ...