Power Analysis for Sample Size Calculations

🎤  Elaine Eisenbeisz      |  📅  April 18, 2024   |  🕒  11 AM Eastern Time US

Description: In this webinar attendees will learn the statistical power analysis and techniques for determining sample size (a priori techniques) calculation. Also attendees will get work examples in the free to use G*Power software. Some code and demonstrations will be provided for powering studies and performing power analysis simulations in R software. Questions related to the feasibility of a study can be answered by power analysis: – How large of a sample will I need to collect in order to see a significant effect? – How many subjects will I need if I test an effect that is a bit larger? a bit smaller? Answers to questions like these will give you an idea if your study is indeed “do-able.”

^{Why You Should Attend:} 

The power of your study is the probability that you will find a statistically significant difference or relationship (an “effect”) if that difference or relationship (effect) truly exists in the population.

A study with too small of a sample size is under-powered. This means that even if the effect you are testing for truly exists, you won’t achieve statistical significance. You will waste time by collecting a sample that is too small to properly power a study. Why perform a research if you can’t see significance for your desired effect?

A study with too large of a sample is over-powered. This means that you’ve collected such a large sample that you will see significance even on very small effects. However, the costs of subject recruitment, data collection, and follow-up (if needed) are quite large. Recruiting more subjects than needed unnecessarily inflates the temporal and monetary costs.