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Measurement Models and CFA; Chi-square and RMSEA. Ulf H. Olsson Professor of Statistics. CFA and ML. k is the number of manifest variables.
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Measurement Models andCFA; Chi-square and RMSEA Ulf H. Olsson Professor of Statistics
CFA and ML k is the number of manifest variables. If the observed variables comes from a multivariate normal distribution, and the model holds in the population, then Ulf H. Olsson
Testing Exact Fit Ulf H. Olsson
Problems with the chi-square test • The chi-square tends to be large in large samples if the model does not hold • It is based on the assumption that the model holds in the population • It is assumed that the observed variables comes from a multivariate normal distribution • => The chi-square test might be to strict, since it is based on unreasonable assumptions?! Ulf H. Olsson
Alternative test- Testing Close fit Ulf H. Olsson
How to Use RMSEA • Use the 90% Confidence interval for EA • Use The P-value for EA • RMSEA as a descriptive Measure • RMSEA< 0.05 Good Fit • 0.05 < RMSEA < 0.08 Acceptable Fit • RMSEA > 0.10 Not Acceptable Fit Ulf H. Olsson
Other Fit Indices • CN • RMR • GFI • AGFI • Evaluation of Reliability • MI: Modification Indices Ulf H. Olsson
Model evaluation • Does the model fit the data • Chi-square; RMSEA and other descriptive measures • Are the measures reliable? • Are the paths (coeffisients) significant? • Is it possible to improve fit? • Modification indices Ulf H. Olsson