Consider the 23 shown below:

When running a designed experiment, it is sometimes difficult to reach and hold the precise factor levels required by the design. Small discrepancies are not important, but large ones are potentially of more concern. To illustrate, the experiment presented in Table P6.16 shows a variation of the 23 design above, where many of the test combinations are not exactly the ones specified in the design. Most of the difficulty seems to have occurred with the temperature variable.
Fit a first-order model to both the original data and the data in Table P6.16. Compare the inference from the two models.
What conclusions can you draw from this simple example?
6.53 In two-level design, the expected value of a nonsignificant factor effect is zero.

(a) True

(b) False

Process Variables Coded Variables 68 Temp Pressure Conc Run (C) (psig) (g/l) x1 X2 X3 Yield, y 1 120 40 12 23 +56=2 160 40 120 80 555 -1 32 46 15 57 57 48 4 160 80 15 65 36 120 40 30 36 160 40 30 7 120 80 30 8 160 80 30 1 9 140 60 22.5 0 0 0 10 140 60 22.5 0 0 0 11 140 60 22.5 0 0 0 140 60 22.5 0 0 0 4 2 2 28 48 57 57 32 46 68 50 44 53 56 Temp-140 x1 20 Pressure-60 20 Conc-22.5 75 22 65