## Lesson 8: Multiple Regression Variable Selection Procedures

Review:

- Intro to Multiple Regression
- Portfolio scores
- Exam 1 Retake

Presentation:

- Variable Selection Procedures
- Variable Selection
- Backward Elimination then Forward Selection
- Demonstrate with East Pueblo RE Sales 2014-2016

- F-Statistic
- Modeling Objective:
- Achieve highest R^2 possible
- For some data this may be below 0.50
- Don’t sacrifice too much significance for small gains in R^2

- Achieve high F-statistic
- Fewer variables = generally preferable (keep it simple)
- Significance of F (p-value) should be <0.05, lower is better
- Individual variables should have p-value < 0.05
- Occasionally it’s appropriate to make exceptions

- Achieve highest R^2 possible

Assignment (complete by Monday):

- Produce a model to estimate MLB winning percentage
- Use 2013 MLB Team statistics
- Test all variables using one or more of the selection procedures above
- Produce a Final Model, aiming to maximize R^2 and F-Statistic
- Add to your portfolio