An experimental design strategy is presented for the purpose of obtaining efficient and statistically reliable data for the evaluation of multi-variable parameter effects on crash-impact and passive occupant protection materials. Two methods in particular, the factorial and the box-Behnken, are presented and applied to a variety of energy-absorbing materials including: Ethafoam, Ensolite, Sorbothane, and expanded bead polystyrene. Results of the study suggest that Sorbothane could be used to effectively reduce injury potential in vehicle areas which are size constrained from using lighter but thicker energy-absorbing padding materials. The factorial method is also used to demonstrate qualitative evaluation of data obtained from the National Highway Transportation Safety Administration Thoracic Side Impact Protection Research Program. The results of this phase of the paper indicate the high level of importance associated with side-impact occupant protection materials.