GLM or General Linear Model is a general tool for ANOVA. As such, we see that it will run studies from factors 1 to 31, and can include nesting or random factors.

For this example, we will look at a larger dataset. The data is for crash test dummies that have been used to look at forces in controlled crash environments. The National Transportation Safety Board collected data from crashing vehicles into a wall at 35 mph. Columns contain information on the make and model of the car. Head injury criterion, chest deceleration, left femur load, right femur load, D/P (whether the dummy was in the driver or passenger seat), protection, doors, year of the car, weight in pounds, and size of the vehicle.

We will look at a few of the factors to study the effect on chest deceleration. It is not possible to investigate all interactions in the data. This is due to some missing values in the results, and not all combinations of levels are possible. We will start by focusing...