# G*Power 3 - Phần mềm tính cỡ mẫu và năng lực

## March 5, 2013 by Admin

G*Power 3 is a major extension of, and improvement over, G*Power 2. It covers statistical power analyses for many different statistical tests of the

*F*test,*t*test,- χ
^{2}-test and - z test families and some
- exact tests.

G*Power 3 offers five different types of statistical power analysis:

- A priori (sample size
*N*is computed as a function of power level 1-β, significance level α, and the to-be-detected population effect size) - Compromise (both α and 1-β are computed as functions of effect size,
*N*, and an error probability ratio*q*= β/α) - Criterion (α and the associated decision criterion are computed as a function of 1-β, the effect size, and
*N*) - Post-hoc (1-β is computed as a function of α, the population effect size, and
*N*) - Sensitivity (population effect size is computed as a function of α, 1-β, and
*N*)

G*Power 3 provides improved effect size calculators and graphics options. It supports both a distribution-based and a design-based input mode.

G*Power 3 is available for Mac OS X 10.4 and Windows XP/Vista. G*Power 3 is free.

Download G*Power

... 3.1.6 for Windows XP, Vista, or 7 (32 and 64 bit) (10 MB) [download]

Windows users:

Please make sure to choose "unpack with folders" in your unzip tool.

... 3.1.6 for Mac OS X 10.6 to 10.8 (2 MB) [download]

Please note that Apple’s new Xcode (which we used for G*Power 3.1.4 and up) only supports Mac OS X 10.6 or later. Thus, if you have Mac OS X 10.4 or 10.5, you need to use G*Power 3.1.3 (2 MB) [download].

Macintosh Power-PC users:

Please note that the development of the Power-PC version of G*Power has been discontinued. However, Power-PC users can still download G*Power 3.1.3 for Power-PC. [download PPC version]