The use of computer-generated designs (CGDs) in research is becoming
more popular during the last 20 years thanks to the availability of CGDs
software . Below are situations where CGDs are appropriate:
- An irregular shaped experimental region: In this situation, the
experimental region is under constraint such as the one for designs of
- A nonstandard model: There are situations where experimenters due to
their knowledge of the studied process might use models other than the
commonly used ones.
- Unusual sample size requirements: Instead of adjusting the experimental
material to the standard designs, experimenters could use a more flexible
- Augmenting a design:
There are situations in which experimenters have to augment an existing design with additional design points
or additional factors. Augmenting a design can easily be done with the help
of a computer.
- Blocking a design: Most experimental material
in agriculture and industry are heterogeneous in nature and therefore its
statistical analysis benefits from blocking. Like augmenting a design,
blocking a design can easily be done with the help of a computer.
- CGDs are better than standard designs: Most partially balanced
incomplete block designs (PBIBDs) are inferior to the
corresponding CGDs in terms of the
goodness of the design. The same thing can be said about balanced
fractional factorial designs. Recently, we have shown that all seven PBIBD-based Box-Behnken
designs are not as good as the corresponding CGDs in terms of rotatability
as well as D- and G-efficiencies.
Recognizing the importance of CGDs in research,
Design Computing is set up to:
The Gendex DOE toolkit
has been used to achieve the first two objectives.
- Promote a new philosophy of designing
experiments, i.e. Design for the experiment, do not experiment for the
- Promote the use of CGDs in industrial
settings where it is difficult to adjust the experimental materials to published
plans and in remote agricultural research stations where it is easier
to get access to a PC than to various catalogues and professional journals to
find a usable plan;
- Foster research and research cooperation in