Sample Size

The number of units (persons, animals, patients, specified circumstances, etc.) in a population to be studied. The sample size should be big enough to have a high likelihood of detecting a true difference between two groups. (From Wassertheil-Smoller, Biostatistics and epidemiology, 1990, p95)


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a larger <b>sample size</b> is
a larger sample size is

with a one-sided test.
with a one-sided test.

calculate the <b>sample size</b>
calculate the sample size

power versus <b>sample size</b>
power versus sample size

Required <b>Sample Size</b> to
Required Sample Size to

<b>sample size</b> calculator
sample size calculator

<b>Sample Size</b> Determination
Sample Size Determination

Choose <b>sample size</b>
Choose sample size

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Sample size determinationPilot experimentRegression analysisInsensitivity to sample sizePASS Sample Size SoftwareStudent's t-testFisher's exact testLivyatan melvilleiCretolamnaTenorite

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Last update: April 2009