UCLA Power Analysis Calculator
Introduction & Importance
UCLA Power Analysis Calculator is an essential tool for researchers and statisticians to determine the appropriate sample size for a study, ensuring that it has enough power to detect an effect if one exists.
How to Use This Calculator
- Enter the sample size, significance level, and desired power.
- Select the effect size.
- Click ‘Calculate’.
- View the results and chart below.
Formula & Methodology
The calculator uses the formula for power analysis, which involves the chosen significance level, desired power, and effect size.
Real-World Examples
Data & Statistics
| Effect Size | Sample Size (n) | Power (1 – β) |
|---|---|---|
| Small | 128 | 0.8 |
| Medium | 64 | 0.8 |
| Large | 32 | 0.8 |
Expert Tips
- Always consider the trade-off between sample size and power.
- Be mindful of the assumptions behind the chosen effect size.
Interactive FAQ
What is power in statistics?
Power is the probability that a statistical test will reject the null hypothesis when the alternative hypothesis is true.
For more information, see the CDC’s online calculator guide and the UNC’s power analysis tutorial.