An article in Industrial and Engineering Chemistry ("More on Planning Experiments to Increase Research Efficiency", 1970, pp.60-65) uses a 25-2design to investigate the effect of A=condensation temperature, B=amount of materials, C=solvent volume, D=condensation time, and E=amount of material 3 on yield. The results obtained are as follows:
e=23.2 ad=16.9 cd=23.8 bde=16.8
ab=15.5 bc=16.2 ace=23.4 abcde= 18.1
a) Verify and comment that the design generators used were I=ACE and I=BDE.
b) Write down the complete defining relation and the aliases for this design.
c) Estimate the main effects.
d) Prepare an analysis of variance table and verify that the AB and AD interactions are available to use as error.
e) Plot the residuals versus the fitted values. Also construct a normal probability plot of the residuals. Comment on the results. Consider the 27-2 design by choosing two four-factor interactions as the independent generators
f) Write down the complete alias structures for this design.
g) Outline the analysis of variance table.
h) What is the resolution of this design