About Orthogonal Design

[Anteneh]

I have 3 factors with 3 levels for each experiment which is 27 treatment combinations but due to limited space my proferssor asked me to use orthogonal design and he told me to make around 17. but i don't have experience about it. How do I make the design from 27 to 17? Is there any design generator? I want to study all treatment combinations but I am afraid that some combination will  ot be studied if I decrease the treatment combinations. Any one who has information about orthogonal experimental design, please help me. Thank you

[PaigeMiller]

You could use PROC OPTEX. This won't produce an orthogonal design, but it will try to get (in layman's terms) as close to orthogonal as possible.

[WarrenKuhfeld]

Don't use Optex. Use MktEx.

%mktex(3 3 3, n=17)

Better yet,

%mktex(3 3 3, n=9)

or

%mktex(3 3 3, n=18)

%mktex will use OPTEX if nothing else is better, but it has other methods that often work better.

https://support.sas.com/rnd/app/macros/MktEx/MktEx.pdf

For a very small problem such as this, OPTEX, and most any other reasonable method will work the same. However, for larger problems, %mktex will often work better than OPTEX.