Certified Six Sigma Black Belt Exam Design of Experiments (DOE) 3

Question 1

When analyzing a DOE, a significant interaction between two factors means:

Accepted Answer

The effect of one factor depends on the level of the other factor

Answer

A significant interaction means the effect of Factor A on the response changes depending on which level of Factor B is set, so factors cannot be interpreted independently.

Question 2

What is the signal-to-noise (S/N) ratio in Taguchi methods primarily used to measure?

Accepted Answer

The robustness of a product or process response to noise factors

Answer

Taguchi's S/N ratio quantifies how much variation (noise) exists relative to the mean signal, with higher S/N indicating more robust performance.

Question 3

In a 2^(4-1) fractional factorial experiment, how many runs are required?

Accepted Answer

8

Answer

A 2^(4-1) design is a half-fraction of a full 2^4 = 16 run design, so it requires 2^(4-1) = 2^3 = 8 runs.

Question 4

Which DOE term describes the difference in response between the high and low levels of a factor, averaged across all other factor combinations?

Accepted Answer

Main effect

Answer

The main effect of a factor is the average change in response when moving from the low level to the high level, averaged over all levels of other factors.

Question 5

A normal probability plot of effects in a factorial experiment is used to:

Accepted Answer

Identify which effects are statistically significant versus noise

Answer

On a normal probability plot, insignificant effects fall on a straight line (noise), while significant effects deviate noticeably from the line.

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Design of Experiments (DOE) 3