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Laboratory
Sample size and power
Before you start a study, compute the sample size you need or the power you can expect.
Sample size and power
Result
- Power
- 1,0000
- Size per group
- 2 : 2
- Total size
- 4
- Effect size
- d = 0,5000
- Noncentrality parameter
- 0,5000
- Critical value
- 0,000029
- Degrees of freedom
- 2,00
The computation is made before the study, from an assumed effect size.
When the allocation ratio differs from 1, each group's size is reported separately.
Sample size and statistical power — Laboratoriya
The effect size you enter is an assumption about the population, not an estimate taken from data.
This calculator computes power BEFORE a study. It does not compute “achieved power” from a finished result: that number is fully determined by the p-value and adds no information.