topic Re: Hunter Screening Design in New SAS User

Hunter Screening Design

HelenaB — Fri, 28 Jun 2019 10:04:31 GMT

Good morning!

I found L18 Hunter Screening Design referred in an article that used JMP (in attachment). Can anyone clarify what type of design is this? I cannot found much about it in the literature.

Thank you in advance!

Re: Hunter Screening Design

Rick_SAS — Mon, 01 Jul 2019 10:06:56 GMT

The JMP community has a separate discussion forum for JMP questions

You might want to ask your question there..

Re: Hunter Screening Design

HelenaB — Wed, 10 Jul 2019 14:44:41 GMT

Thank you for the suggestion! I already reposted the question in that discussion forum.

Re: Hunter Screening Design

PaigeMiller — Wed, 10 Jul 2019 14:55:19 GMT

L18 is a design that was popularized by Genichi Taguchi. It has one variable which is at three levels and the remainder are at two levels. It is orthogonal for main effects only, but interactions are partially confounded with main effects and with other interactions.

Re: Hunter Screening Design

HelenaB — Thu, 11 Jul 2019 11:52:34 GMT

Paige Miller,

Thanks for your help. The definition that you gave is perfectly in accordance with the characteristics of the L18 Hunter screening Design that I found in the attached article. However, I also found this reference https://www.itl.nist.gov/div898/handbook/pri/section3/pri33a.htm that presents other definition for L18 Designs - 1 factor at two levels and seven factors at 3 levels. I would like to have your opinion on it.

Thank you again,

Helena

Re: Hunter Screening Design

PaigeMiller — Thu, 11 Jul 2019 12:17:16 GMT

That L18 is 2 x 3^(7–5) design, which is orthogonal if you have main effects only. The interactions would be non-estimable, and highly confounded with main effects. I would not use this in the presence of interactions — except perhaps as a screening design to identify "active" factors, and even then one significant interaction can destroy the validity of the results from this design, this is a risk of all highly fractionated designs.

Re: Hunter Screening Design

HelenaB — Thu, 11 Jul 2019 14:42:52 GMT

But we can say that L18 2 x 3^(7–5) design is a L18 fractional factorial design?

Re: Hunter Screening Design

PaigeMiller — Thu, 11 Jul 2019 15:00:24 GMT

It is a mixed-level fractional factorial design. It doesn't really matter what name it has, L18 or otherwise.

Re: Hunter Screening Design

HelenaB — Thu, 11 Jul 2019 15:03:06 GMT

Thank you for your very helpful informations!

Re: Hunter Screening Design

HelenaB — Mon, 15 Jul 2019 00:04:44 GMT

Still regarding this answer:

"It is a mixed-level fractional factorial design. It doesn't really matter what name it has, L18 or otherwise.

--
Paige Miller"

Is a L18 or other mixed-level fractional factorial design capable of generate a quadratic model, or just a main effects one? If yes, under which circunstances?