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Story Name: Crash Test Dummies
Story Topics: Engineering , Health 
Datafile Name: CrashTest.data
Methods: ANOVA , ANCOVA , Transformation 
Abstract: Stock automobiles containing dummies in the driver and front passenger seats crashed into a wall at 35 miles per hour. National Transportation Safety Board officials collected information how the crash affected the dummies. The injury variables describe the extent of head injuries, chest deceleration, and left and right femur load. The datafile also contains information on the type and safety features of each crashed car.

One way to evaluate the relationship between car features and crash injuries is using ANOVA with the various injury variables as dependent variables. Histograms of the injury variables shows that all of them are skewed right. Taking the logs of these variables results in approximately normal distributions. You may also want to take the log of the weight variable.

 The variables D/P, Protection, Doors, and Size all show significant F-tests when included in an analysis of variance model with no interactions and the log of head injury criterion as the dependent variable. Year and the log of weight are not significant when included as covariates with these variables in an analysis of covariance. However, the log of weight is significant when the dependent variable is either left or right femur load.

 This dataset also lends itself more advanced linear models such as MANOVA and models with various interaction terms.

Image: ANOVA table

Reference: National Transportation Safety Administration
Authorization: free use
Description: Data based on trials in which stock automobiles are crashed into a wall at 35MPH with dummies in the driver and front passenger seat.

Number of cases: 352
Variable Names:
  1. make: Car make
  2. Model: Model of that car
  3. carID: Usually the combination of make and model
  4. carID & Year: Full ID of the car
  5. Head_IC: Head injury criterion
  6. Chest_decel: Chest deceleration
  7. L_Leg: Left femur load
  8. R_Leg: Right femur load
  9. D/P: Whether the dummy is in the Driver or Passenger seat
  10. Protection: Kind of protection (seat belt, air bag, etc.)
  11. Doors: Number of doors on the car
  12. Year: Year of the car
  13. Wt: Weight in pounds
  14. Size: A categorical variable to classify the cars to a type (light, minivan)