The article Optimum Design of an A-pillar Trim with Rib Structures for Occupant Head Protection (H. Kim and S. Kang, Proceedings of the Institution of

The article €œOptimum Design of an A-pillar Trim with Rib Structures for Occupant Head Protection€ (H. Kim and S. Kang, Proceedings of the Institution of Mechanical Engineers, 2001:1161€“1169) discusses a study in which several types of A-pillars were compared to determine which provided the greatest protection to occupants of automobiles during a collision. Following is a one-way ANOVA table, where the treatments are three levels of longitudinal spacing of the rib (the article also discussed two insignificant factors, which are omitted here). There were nine replicates at each level. The response is the head injury criterion (HIC), which is a unitless quantity that measures the impact energy absorption of the pillar.

The treatment means were

a. Can you conclude that the longitudinal spacing affects the absorption of impact energy?

b. Use the Tukey€“Kramer method to determine which pairs of treatment means, if any, are different at the 5% level.

c. Use the Bonferroni method to determine which pairs of treatment means, if any, are different at the 5% level.

d. Which method is more powerful in this case, the Tukey€“Kramer method or the Bonferroni method?

Treatment Mean A B 930.87 873.14 979.41