Research Power Analysis Calculator
Research power analysis is a crucial step in planning a study. It helps determine the sample size required to detect an effect of a given size with a specified level of confidence.
How to Use This Calculator
- Enter the sample size (n).
- Select the significance level (α).
- Enter the effect size (d).
- Click “Calculate”.
Formula & Methodology
The calculator uses the formula for power analysis based on Cohen’s d:
Power = 1 – β = Z_α/2 * (Z_β + Z_α/2 * d / √n)
Real-World Examples
Data & Statistics
| Effect Size (d) | Power (80% confidence, n=50) |
|---|---|
| 0.2 | 0.12 |
| 0.5 | 0.76 |
| 0.8 | 0.99 |
Expert Tips
- Power analysis should be done before starting a study.
- Consider the trade-off between sample size and effect size.
- Use the results to guide your study design.
Interactive FAQ
What is effect size?
Effect size is a measure of the magnitude of a phenomenon.