Minitab provides two optimality criteria for the selection of design points, as follows:
D-optimality
The D-optimality criterion minimizes the determinant of the variance-covariance matrix of the regression coefficients. You specify the model, then Minitab selects design points that satisfy the D-optimal criterion from a set of candidate design points.
Distance-based optimality
Distance-based optimality spreads the design points uniformly over the design space. Use this method when it is not possible or desirable to select a model before you begin. Distance-based optimality is not available with general full factorial designs.
