Analyze Factorial Design

Two-Level Split-Plot Designs
Estimated Coefficients Using Uncoded Units - Regression Equation Coefficients

  

Minitab displays the coefficients in uncoded units in addition to coded units if the two units differ.

For each term in the model, there is a coefficient. Use these coefficients to construct an equation representing the relationship between the response and the factors.

To use this equation, plug in the uncoded (actual) factor values and calculate the predicted response. Because these coefficients are estimated using uncoded units, putting coded factor values into this equation would yield incorrect predictions about strength.

Example Output

Regression Equation in Uncoded Units

 

Resistance = 50.875 - 4.025 Pretreatment[HTC] - 0.025 Stain + 2.242 Pretreatment[HTC]*Stain

 

Equation averaged over whole plots.

Interpretation

For the water resistance data, the regression equation is:

Resistance = 50.875 - 4.025 (Pretreatment [HTC]) - 0.025 (Stain) + 2.242 (Pretreatment [HTC] * Stain)