A consulting firm engaged in road-building work is asked by one of its clients to carry out an experimental study to determine the effects of six factors on the physical properties of a certain kind of asphalt. Call these factors A, B, C, D, E, and F.
(a) If a full factorial design is used, how many runs are needed?
(b) Construct a two-level resolution IV design requiring 16 runs.
(c) What is the defining relation for this 16-run design?
(d) What effects are confound with the main effect A, with the BD interaction?