11/3/2011

Comments on homework - please download your R scripts to your hw folder on Microwave.

In class exercises

• Modify Bodyfat.R to fit a model with all pairwise interaction terms and then use the partial F-test to see if any of the interaction terms are needed in the model.
• Modify Firms.R to fit two separate regression lines and conduct formal hypothesis tests to see if two lines are better than one for predicting the number of months elapsed since the insurance innovation was introduced.

All possible subsets - see handout

Automatic search procedures - see Surgery-Auto.R

We will have a problem session on Tuesday.