Design of Experiments (DOE) Flashcards
7 cards from real Certified Six Sigma Black Belt Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Design of Experiments (DOE) flashcards as text
In a 2^k factorial design, what does the 'k' represent?
Answer: The number of factors
In a 2^k factorial design, k is the number of factors and 2 represents the number of levels (high and low) for each factor.
Which type of DOE design is most appropriate when the experimenter suspects curvature in the response surface?
Answer: Central Composite Design (CCD)
Central Composite Design (CCD) includes axial (star) points that allow estimation of quadratic effects and detection of curvature.
What is the primary purpose of randomization in a designed experiment?
Answer: To guard against lurking variables and time-related effects
Randomization distributes the effects of unknown nuisance variables across all experimental runs, preventing systematic bias.
In a fractional factorial design, a resolution III design means:
Answer: Main effects are confounded with 2-factor interactions
In a resolution III design, main effects are aliased (confounded) with 2-factor interactions, so they cannot be separately estimated.
A Plackett-Burman design is best used for:
Answer: Screening many factors to identify the vital few
Plackett-Burman designs are highly efficient screening designs that study many factors in relatively few runs to identify significant main effects.
What is the alias structure in a fractional factorial design?
Answer: The relationship showing which effects are confounded with each other
The alias structure defines which effects are indistinguishable from each other due to the fraction chosen in the experimental design.
In DOE, what is a 'center point' used for?
Answer: To estimate pure error and check for curvature without additional factor combinations
Center points are runs at the midpoint of all factor ranges; they provide an estimate of pure experimental error and can detect curvature in the response.