Basic concepts in the determination of sample size and power analysis for 1) estimation of a mean or proportion from one sample and 2) comparison of means or proportions from two samples will be introduced. The hypothesis testing framework will be introduced and consideration will be given to specifying the null hypothesis, the alternative hypothesis, Type 1 (alpha) error and Type 2 (beta error). The concepts of power and minimum detectable effect (MDE) size within this framework will be presented. These key concepts will be expanded upon in the presentations that follow.