I went through a "design of experiment" course recently, but there are still things that I haven't sorted out yet regarding which types of experiment to choose when facing a real world problem.
I understand that experiments can be costly, so one may be inclined to use a fractional design over a full factorial design (Taguchi, Box-Benkhen) for instance. But are there general guidelines to which types of design to choose ? Is cost the only issue ?
I come across many theoretical designs through books, but I can't grasp why some types of experimental designs are used instead of others. I am probably lacking something here, so if anyone can help me sort this out it will be deeply appreciated.