Mixture Optimal Design Selection

Search: Best or Coordinate Exchange or Point Exchange

Optimality: choose from I-, D-, and A- optimal designs. Also available and not recommended are modified distance and “pure” distance based design criterion.

Runs: Shows the number of points and the purpose for which they are selected.

Required model points is the minimum number of runs to estimate the coefficients of the terms in the designed for model specified under the Edit model button.

Additional model points are extra runs added to the experiment to improve precision estimates or coverage of the factor space.

Lack-of-fit points provide extra points to fill the factor space. The extra information provided by these points can test the fit of the model.

Replicate points are chosen to support the optimality and provide an estimate of pure error.

Additional center points are added as requested.

Total runs is the sum of all the above.

Edit model: The software will default to a certain type of model, depending on the type of optimal design you are creating. You may customize the model by clicking on the Edit Model button. Adding or subtracting specific terms in a model will alter both the number of runs and specifically which runs are chosen. For more information use the help button on the Edit model button.

Blocks: allows the design to be separated into blocks. Adding blocks will add runs to your design to provide additional degrees of freedom to estimate the block effects while allowing useful analysis for the model coefficients.

Options: The more random starts and loops that are allowed the better the design will meet the chosen optimality criterion. For more details use the help button found on the Options dialog.

Edit Candidate Points: Click this button if are using point exchange and want to limit the type of points the design can consider.

Force categoric balance: only appears when there are categoric factors. This option makes it so the levels of a categoric factor will be as evenly distributed as possible. It is not required and may negatively impact the overall structure of the design.