Root Mean Squared Error of Approximation from chisq, df, and n

Find the RMSEA from model chi square, degrees of freedom and number of observations. Show confidence intervals.

RMSEA(chisq, dof, n.obs, alpha = 0.1)

Arguments

chisq: The Chi square statistic from an analysis
dof: Degrees of freedom of the model
n.obs: Number of observations
alpha: alpha level for confidence intervals

Details

RMSEA is just a chisquare adjusted by its degrees of freedom and the sample size. \(\sqrt{chisq/(dof * (nobs)) -1/(n.obs -1)}\). It is given in most of the appropriate functions (e.g.,fa) and given here for completeness.

Value

RMSEA: the estimated value
RMSEA-L: the lower bound
RMSEA-U: the upper bound

References

Steiger, J. H.,and Lind, J. C. (1980). Statistically based tests for the number of common factors. Paper presented at the Annual Meeting of the Psychometric Society, Iowa City, IA.

Author

William Revelle