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The main application of statistical power is "power analysis", a calculation of power usually done before an experiment is conducted using data from pilot studies or a literature review. Power analyses can be used to calculate the minimum sample size required so that one can be reasonably likely to detect an effect of a given size (in other ...
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.
A priori analyses are one of the most commonly used analyses in research and calculate the needed sample size in order to achieve a sufficient power level and requires inputted values for alpha and effect size. Compromise analyses find implied power based on the beta/alpha ratio, or q, and inputted values for effect size and sample size ...
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 based on the cost, time, or convenience of collecting the data, and the need for it to offer sufficient statistical power. In complex studies ...
PASS is a computer program for estimating sample size or determining the power of a statistical test or confidence interval. NCSS LLC is the company that produces PASS. NCSS LLC also produces NCSS (for statistical analysis). PASS includes over 920 documented sample size and power procedures.
nQuery is a clinical trial design platform used for the design and monitoring of adaptive, group sequential, and fixed sample size trials. It is most commonly used by biostatisticians to calculate sample size and statistical power for adaptive clinical trial design. nQuery is proprietary software developed and distributed by Statsols. The ...
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So in the calculation of the weighted mean is in fact based on a ratio estimator, with an estimator of the total at the numerator and an estimator of the population size in the denominator (making the variance calculation to be more complex).