Welcome to the Companion Site!

This site is intended to enhance your use of Introduction to Power Analysis: Two Group Studies, First Edition, by E. C. Hedberg.

Introduction to Power Analysis: Two-Group Studies provides readers with the background, examples, and explanation they need to read technical papers and materials that include complex power analyses. This clear and accessible guide explains the components of test statistics and their sampling distributions, and author E. C. Hedberg walks the reader through the simple and complex considerations of this research question. Filled with graphics and examples, the reader is taken on a tour of power analyses from covariates to clusters, seeing how the complicated task of comparing two groups, and the power analysis, can be made easy.

Example power analyses using SPSS, Stata, and R, complete with code and output, are available to accompany the material in Chapters 3-7:





We gratefully acknowledge E. C. Hedberg for writing an excellent text and creating the materials on this site.