Multi-Variable experiments Factor= Number of independent variables Four-Factor experiment has 4 independent variables Level a given value of an independent variable Numerical -200 300 400 Qualitative- Brand x, brand y, brand z Full-Factorial Experiment All factors at all levels May lead to a huge number of data points Fractional-Factorial Experiment Expert judgement: carefully selected subset Adaptive: decide as you get some data Design of Experiments Taguchi, orthogonal arrays Beyond scope of 16.62X5 Multi-Variable Experiments – Factor = Number of independent variables • Four-Factor experiment has 4 independent variables – Level = A given value of an independent variable • Numerical – 200, 300, 400 … • Qualitative – Brand x, Brand y, Brand z … – Full-Factorial Experiment • All factors at all levels • May lead to a huge number of data points. – Fractional-Factorial Experiment • Expert judgement: carefully selected subset • Adaptive: decide as you get some data • Design of Experiments: Taguchi, orthogonal arrays – Beyond scope of 16.62X