Six Sigma Green Belt Certification Practice Exam

In an experiment testing the effect of weight on the elasticity of a material, what do the weights represent?

1. Main Effect

2. Factors

3. Levels

4. Residuals

The correct answer is: Levels

The weights in the experiment testing the effect of weight on the elasticity of a material represent levels. In the context of experimental design, levels refer to the different values or categories that a factor can take during the experiment. Since the weights are being tested at various amounts to observe their impact on the material's elasticity, each specific weight is a different level of the factor (weight). Understanding that levels help to demonstrate how changes in the factor (in this case, weight) can influence the outcome of the experiment (elasticity) is key. By systematically varying the levels of the weight, the experiment can assess the relationship and effects more accurately. Main effect pertains to the overall effect of a single factor on the response variable but does not denote the specific distinct values that a factor can take. Factors themselves are the elements being tested—such as weight—but they are not the actual values tested. Residuals refer to the variance in the response variable that cannot be explained by the model, which is unrelated to the concept of levels in this context.