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Survey methodology textbooks generally consider simple random sampling without replacement as the benchmark to compute the relative efficiency of other sampling approaches. [ 3 ] An unbiased random selection of individuals is important so that if many samples were drawn, the average sample would accurately represent the population.
Reservoir sampling is a family of randomized algorithms for choosing a simple random sample, without replacement, of k items from a population of unknown size n in a single pass over the items. The size of the population n is not known to the algorithm and is typically too large for all n items to fit into main memory .
Before modern computing, researchers requiring random numbers would either generate them through various means (dice, cards, roulette wheels, [5] etc.) or use existing random number tables. The first attempt to provide researchers with a ready supply of random digits was in 1927, when the Cambridge University Press published a table of 41,600 ...
The ratio of uniforms is a method initially proposed by Kinderman and Monahan in 1977 [1] for pseudo-random number sampling, that is, for drawing random samples from a statistical distribution. Like rejection sampling and inverse transform sampling, it is an exact simulation method. The basic idea of the method is to use a change of variables ...
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]
Given a random point underneath a probability density curve, its x coordinate is a random number with the desired distribution. The distribution the ziggurat algorithm chooses from is made up of n equal-area regions; n − 1 rectangles that cover the bulk of the desired distribution, on top of a non-rectangular base that includes the tail of ...
Latin hypercube sampling (LHS) is a statistical method for generating a near-random sample of parameter values from a multidimensional distribution. The sampling method is often used to construct computer experiments or for Monte Carlo integration. [1] LHS was described by Michael McKay of Los Alamos National Laboratory in 1979. [1]
Matched or independent study designs may be used. Power, sample size, and the detectable alternative hypothesis are interrelated. The user specifies any two of these three quantities and the program derives the third. A description of each calculation, written in English, is generated and may be copied into the user's documents.