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2. 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 ...

3. Design effect - Wikipedia

   en.wikipedia.org/wiki/Design_effect

   In survey methodology, the design effect (generally denoted as , , or ) is a measure of the expected impact of a sampling design on the variance of an estimator for some parameter of a population. It is calculated as the ratio of the variance of an estimator based on a sample from an (often) complex sampling design, to the variance of an ...

4. Student's t-test - Wikipedia

   en.wikipedia.org/wiki/Student's_t-test

   In these formulae, n i − 1 is the number of degrees of freedom for each group, and the total sample size minus two (that is, n 1 + n 2 − 2) is the total number of degrees of freedom, which is used in significance testing. Equal or unequal sample sizes, unequal variances (s X 1 > 2s X 2 or s X 2 > 2s X 1

5. Pearson correlation coefficient - Wikipedia

   en.wikipedia.org/wiki/Pearson_correlation...

   Sample size. If the sample size is moderate or large and the population is normal, then, in the case of the bivariate normal distribution, the sample correlation coefficient is the maximum likelihood estimate of the population correlation coefficient, and is asymptotically unbiased and efficient, which roughly means that it is impossible to ...

6. Point-biserial correlation coefficient - Wikipedia

   en.wikipedia.org/wiki/Point-biserial_correlation...

   Further, n 1 is the number of data points in group 1, n 0 is the number of data points in group 2 and n is the total sample size. This formula is a computational formula that has been derived from the formula for r XY in order to reduce steps in the calculation; it is easier to compute than r XY. There is an equivalent formula that uses s n−1:

7. Sampling (statistics) - Wikipedia

   en.wikipedia.org/wiki/Sampling_(statistics)

   Sampling (statistics) In statistics, quality assurance, and survey methodology, sampling is the selection of a subset or a statistical sample (termed sample for short) of individuals from within a statistical population to estimate characteristics of the whole population. The subset is meant to reflect the whole population and statisticians ...

8. Effect size - Wikipedia

   en.wikipedia.org/wiki/Effect_size

   In statistics, an effect size is a value measuring the strength of the relationship between two variables in a population, or a sample-based estimate of that quantity. It can refer to the value of a statistic calculated from a sample of data, the value of a parameter for a hypothetical population, or to the equation that operationalizes how statistics or parameters lead to the effect size value.

9. PS Power and Sample Size - Wikipedia

   en.wikipedia.org/wiki/PS_Power_and_Sample_Size

   PS Power and Sample Size Calculator. Windows. Also on Apple and Linux under Wine. Also available as an online tool. [1] PS is an interactive computer program for performing statistical power and sample size calculations. [2] [3] [4]