8.9. R. D. Snee (“Experimenting with a Large Number of Variables,” in Experiments in Industry: Design, Analysis and Interpretation of Results, by R. D. Snee, L. B. Hare, and J. B.

Trout, Editors, ASQC, 1985) describes an experiment in which a 25!1 design with I $ ABCDE was used to investigate the effects of five factors on the color of a chemical product.

The factors are A $ solvent/reactant, B $ catalyst/reactant, C

$ temperature, D $ reactant purity, and E $ reactant pH.

The responses obtained were as follows:

(a) Prepare a normal probability plot of the effects. Which effects seem active?

(b) Calculate the residuals. Construct a normal probability plot of the residuals and plot the residuals versus the fitted values. Comment on the plots.

(c) If any factors are negligible, collapse the 25!1 design into a full factorial in the active factors. Comment on the resulting design, and interpret the results.

Transcribed Image Text:

b = -2.68 e--0.63 d = 6.79 a=> 2.51 ade = 5.47 bde = 3.45 abd=5.68 2.06 cde = 5.22 acd=4.38 abe = 1.66 c = ace = 1.22 bce = -2.09 abc1.93 bcd=4.30 abcde = 4.05