G. Power of a Test of Poor Fit and Sample Sizes Needed for Power

MacCallum et al. (1996) provided SAS syntax for calculating power and sample size using RMSEA values, which can be translated for other general purpose statistical programs. On the website for this book, we provide two R functions that will calculate power and sample size, named rmsea.power() and rmsea.n(), respectively. Both functions require arguments for significance level (alpha), RMSEA under poor fit (rmsea0), population RMSEA (rmseaa), and degrees of freedom (df ). In addition, the rmsea.power() function requires a sample size (n) argument, while the rmsea.n() function requires a desired power (power ) argument.