Six Sigma Green Belt

Answer: D - These gradations are referred to as levels.

Key Takeaway: Levels in experimental designs refer to the settings in the independent variables. For example, gradations in temperature, weight or other measurements are used as levels of independent variables. These levels are then analyzed in terms of other impact on the dependent variable. In this example, the temperature settings can be used to test how long it takes this standard oven to bake a medium-sized pie.