Assignment 13 - Validation of Regression

This builds on Assignment 12 - Multiple Regression. 

Extend the report with the determination of the fit of the data in your model.  Write or add to the previous report with the appropriate statistic. Use this to help.

The Gold Standard Approach

For most engineering applications, use this systematic approach:

1. Start with visualization (scatter plots)
2. Calculate Pearson AND Spearman correlations
3. Test statistical significance (p-values < 0.05)
4. Check mutual information for non-linear patterns
5. Validate with model performance (does including the variable improve predictions?)
6. Consider domain knowledge (does the relationship make physical sense?)

The best indicator isn't just one metric, but a combination of statistical evidence, visual confirmation, and engineering judgment.