Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...

Background: In this article, we discuss the purpose of sample size calculation in clinical trials, the need for it, and the methods by which it is accomplished. Study samples that are either too small ...

Define statistical power List the potential consequences of doing a study that has low power, and also a study that has too much power. Explain what a type 1 and type ...

1. Röhrig B, du Prel JB, Blettner M: Study design in medical research – Part 2 of a series on evaluation of scientific publications [Studiendesign in der medizinischen Forschung. Teil 2 der Serie zur ...