After specifying the regression model and deciding on the population values, Step 2.1. requires checking to make sure the specified values produce the correct results. This can be done in R by estimating the model using the specified parameter values and examining the results. To do this in lavaan, use the sem() function with the fixed.x=FALSE argument. The fixed.x=FALSE argument is required when fixing a predictor variable’s variance or covariance. The fitted() function returns the model-based means and covariances (i.e., those implied by using the fixed parameter values), while the cov2cor() converts a covariance matrix to a correlation matrix. As I used standardized values for the parameters, the covariance and correlation matrices are identical for this example.