cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
JMP is taking Discovery online, April 16 and 18. Register today and join us for interactive sessions featuring popular presentation topics, networking, and discussions with the experts.
Choose Language Hide Translation Bar
Benkh
Level I

DOE Parameter estimate when Interaction of continuous factors are centered by default. How change it

Hi, The design is a Full Factorial(4-Factors) + 1 Center Point + 2 special combos-19 runs-1 Response-4 missing

The 4 factors are continuous (level +1= presence at the highest dose; 0= presence at half dose; -1=absence=dose 0).

In a first stage, I expected to evaluate the importance of interactions and main factors to select the best components to make a product. This is not a mixture design as more than 99.9% of the product is a solvent(only additives without a fixed quantity)

Final Product= combo of 1 to 4 A (A6,A8,A9,A10). Unfortunately the response for 4 runs were invalidated after QC and therefore I don't have sufficient degrees of freedom to estimate the 3-way interactions and the 4-way interaction without simplification of the model. In a first time, I estimate only the 4 main factors and the 6 two-way interactions.

Sorted Parameter Estimates

Term                                                        Estimate                 t-ratio                   Prob>|t|

(A8-0.11667)*(A9+0.01667)                  -0.007222                 -3.41                    0.0271*

A8                                                          -0.006444                 -3.10                    0.0361*

A9                                                           0.01211                     5.90                    0.0041*

I have attached the data in a .jmp file and output, profiler and interaction graphs and comments in a word doc.

The interaction between the 2 continuous factors A8 and A9, centered respectively by their means in the design(0.11667 and -0.01667), was significant indicating that the effect of A8 was clearly negative when A9 was present at its maximum dose(level +1,=higher dose), near zero when A9 was absent(level-1,=dose 0) and intermediate when A9 was at half dose(level 0-half dose). 

The A8 parameter was estimated for A9 at its mean value. Is it possible, with JMP, to have an interaction not centered and respective tests of A8 parameter when A9 was absent(at level -1,=dose 0) or present at the higher dose(at level +1,=higher dose).

1 ACCEPTED SOLUTION

Accepted Solutions

Re: DOE Parameter estimate when Interaction of continuous factors are centered by default. How chang

When you are in the Fit Model set up dialog, there is a red triangle menu next to "Model Specification."  Under that menu is a "center polynomials" option.  Just un-check it. 

 

Best,

 

M

View solution in original post

1 REPLY 1

Re: DOE Parameter estimate when Interaction of continuous factors are centered by default. How chang

When you are in the Fit Model set up dialog, there is a red triangle menu next to "Model Specification."  Under that menu is a "center polynomials" option.  Just un-check it. 

 

Best,

 

M