# Variable Testing

- [Pre-Testing Variables](/mixmodeler-docs/model-building/variable-testing/pre-testing-variables.md): Evaluate Variable Performance Before Model Addition
- [Adstock Optimization](/mixmodeler-docs/model-building/variable-testing/adstock-optimization.md): Find the Optimal Carryover Rate for Each Channel
- [VIF & Multicollinearity](/mixmodeler-docs/model-building/variable-testing/vif-and-multicollinearity.md): Detect and Resolve Variable Redundancy
- [Granger Causality Tests](/mixmodeler-docs/model-building/variable-testing/granger-causality-tests.md): Validate Predictive Relationships in Your Model