(Still under construction but there is some useful information below.)

G*Power is a software that can make sample size calculations and power estimations. It can manage most types of statistical tests except Cox regression. G*Power can be downloaded from Dussedorf University.

## Examples for comparing two groups – T-test and Mann-Whitneys test (click to watch)

Example 1 of sample size calculation for comparing two groups – T-test and Mann-Whitneys test## Example for Logistic regression (click to watch)

Example of sample size calculation for unconditional binary Logistic regression when the independent variable is binary (such as gender)## Useful links

You should cite this article if you use its information in other circumstances. An example of citing this article is:

Ronny Gunnarsson. G*Power [in Science Network TV]. Available at: http://science-network.tv/gpower/. Accessed February 25, 2017.

Ronny Gunnarsson. G*Power [in Science Network TV]. Available at: http://science-network.tv/gpower/. Accessed February 25, 2017.