How to Compare SEM Models in AMOS: A Hands-On Approach

Comparing structural equation modelling (SEM) models in AMOS is vital for selecting the best-fitting model and refining your hypotheses. Here is a practical guide:

1. Model Specification: Create the alternative models you want to compare, each representing a different theoretical structure or hypothesis.
2. Data Preparation: Ensure your data is clean, well-organized, and loaded into AMOS.
3. Estimate Models: Estimate each model separately by clicking “Analyze” and “Estimate Model”. AMOS will provide fit indices and parameter estimates.
4. Model Comparison: To compare models, utilize fit indices such as Chi-square difference tests (Δχ²), Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Comparative Fit Index (CFI), and Root Mean Square Error of Approximation (RMSEA). Lower AIC and BIC values and higher CFI indicate better model fit.
5. Nested Models: If models are nested (one model is a simplified version of another), use Δχ² to assess their difference. A significant Δχ² suggests a significant difference in model fit.
6. Non-nested Models: For non-nested models, compare AIC, BIC, CFI, and RMSEA across models. Select the model with lower AIC and BIC, higher CFI and smaller RMSEA, indicating a better fit.
7. Interpretation: Consider the theoretical implications of your model comparisons and choose the one that best fits the data and the theory.
8. Reporting: Document and report your model comparisons, including fit indices, parameter estimates, and rationale for selecting the best-fitting model.

Comparing SEM models in AMOS allows you to refine your hypotheses, make more informed decisions, and enhance the quality of your research.