Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt Design of Experiments (DOE) Questions and Answers 2

Question 1

In a 2^k factorial design, what does the term 'confounding' refer to?

Accepted Answer

Aliasing a higher-order interaction with a block effect

Answer

Randomizing the run order within each block

Answer

Replicating center points to estimate curvature

Answer

Adding noise factors to the experimental layout

Question 2

A Six Sigma Black Belt runs a 2^4 full factorial with two replicates. How many total experimental runs are required?

Accepted Answer

32

Answer

16

Answer

24

Answer

48

Question 3

Which of the following is the primary advantage of using a fractional factorial design over a full factorial?

Accepted Answer

It reduces the number of runs while still estimating main effects

Answer

It eliminates the need for randomization

Answer

It guarantees detection of all interaction effects

Answer

It removes the requirement for replication

Question 4

What is the resolution of a 2^(5-2) fractional factorial design with generators I=ABCD and I=BCE?

Accepted Answer

Resolution III

Answer

Resolution IV

Answer

Resolution V

Answer

Resolution II

Question 5

In a Response Surface Methodology (RSM) study, what is the purpose of adding axial (star) points to a factorial design?

Accepted Answer

To allow estimation of quadratic (second-order) effects

Answer

To increase the number of blocks in the experiment

Answer

To reduce the total number of runs needed

Answer

To eliminate multicollinearity among factors

Question 6

A Black Belt notices that the residual plot from a DOE shows a funnel shape with increasing spread. What assumption is most likely violated?

Accepted Answer

Constant variance (homoscedasticity)

Answer

Normality of residuals

Answer

Independence of observations

Answer

Linearity of the model