Design of experiments (DOE) is an extremely practical and cost-effective way to study the effects of different factors and their interactions on a response.

But finding your way through DOE-land can be daunting when you’re just getting started. So I’ve enlisted the support of a friendly golden retriever as a guide dog to walk us through a simple DOE screening experiment.

Nala, the golden retriever, is shown at right. Notice how patiently she sits as her picture is being taken. She’s a true virtuoso with the “sit” command.

But “lay down” is another story...

Formulate the objective

Although Nala knows the “lay down” command, she doesn’t perform it quickly or consistently.

Why not? I decided to design a simple experiment to find out. The goal is to screen potential factors and determine which ones, separately or in combination with each other, may be affecting her response to “lay down.”

 …