lecture9_s10 CFA - Confirmatory Factor Analysis Evaluation Psychology 588 Covariance structure and factor models Evaluation 2 Evaluating a model is

# lecture9_s10 CFA - Confirmatory Factor Analysis Evaluation...

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Confirmatory Factor Analysis: Evaluation Psychology 588: Covariance structure and factor models Feb 24, 2010
Evaluating a model is equivalent to testing a hypothesis of a set of constraints (that make whether explicit or implicit), provided that all other assumptions fulfilled --- similar to the logic behind null hypothesis testing All overall fits quantify whether they are statistical or standardized (i.e., bounded by [0,1]) Overall fit indicates goodness (or badness) of the whole model, summarizing into a scalar value Individual fits tell goodness of fit to particular manifest DVs (as indicated by R 2 or SMC) and standard error of parameters indicate how reliable parameter estimates are --- both overall and individual fits should be evaluated! Evaluation 2 ˆ , S Σ ˆ Σ S ˆ S Σ
Residuals indicate how the specified model predicts individual covariances --- note that the variances s ii have no residual in recursive models Sources of residuals: ¾ Σ Σ ( θ ), which we want to know by the residuals ¾ sampling fluctuation --- with large N , smaller residuals are expected if the model is correct ** scale of observed variables determines the size of residuals --- if correlations are analyzed, residuals would not have scale dependency, varying [-2,2] Residuals 3 ˆ ij ij s σ