Sample Size for Descriptive Studies

A sample-size calculator is only as smart as the choices you feed it. This level teaches you to map any study to the right test and formula, then walks you through sizing descriptive studies, estimating a prevalence or a mean, with a hands-on calculator demo.

Who this level is for

Researchers, clinicians and program staff who have a study idea and need to size it, plus anyone who reviews protocols. No coding required. Recommended after Level 1.

What you'll learn

• How outcome type (continuous, binary, time-to-event) decides which formula applies
• How predictor types and group comparisons (one group, two groups, paired vs independent) shape the calculation
• How to map a design to the right test and sample-size formula
• How to compute the sample size to estimate a proportion (prevalence) or a mean
• A hands-on walkthrough estimating a prevalence with Epitools
• Honest, legitimate strategies to reduce the sample size you need

You finish with: The required sample size for a descriptive aim (a prevalence or a mean), at two margins of error.