What is statistical power and how do I determine sample size?

What is statistical power and how do I determine sample size?

Statistical power is the probability of correctly rejecting the null hypothesis when it is false. It helps determine the sample size needed for a study.

Why is statistical power important in research?

Statistical power is crucial because it affects the likelihood of detecting an effect if there is one. Low power can lead to false negatives.

How can I increase the power of my study?

You can increase power by increasing sample size, using a more sensitive measurement, or reducing variability in your data.

What is the typical power level researchers aim for?

Researchers typically aim for a power level of 0.80, meaning there's an 80% chance of detecting an effect if it exists.

Can you explain how to calculate sample size for a given power?

Sure! Sample size can be calculated using formulas that consider the expected effect size, significance level, and desired power.