Update the Model

The current model of the WAIS-III indicated a Heywood case between perceptual organization and processing speed. To fix a highly correlated set of latent variables, you should collapse those two variables into one latent variable. You should make a performance variable that combines the manifest variables for the perceptorg and processing latent variables.

The data has been loaded for you and is called IQdata. You can view the data using head(IQdata).

Edit the four-factor model to include one performance variable measured by piccomp, block, matrixreason, digsym, and symbolsearch.
Use the cfa() function to analyze the model for any new errors.
Summarize the model to determine model fit with the standardized solution and fit indices.

Exercise

Update the Model

Instructions