multi variate question (DOE)!

[dramarc]

Hi!

I received a large quantity of data from one of my students.
The variables (factors) are the final concentration in a bulk solution.
Components A or B are mixed with different ratios of x or y or z...
Water is also used 0 or 0,1%
A and B are present at 0,4 or 0,8 % when added into the bulk solution.
X, y or z is present in 0,4 or 0,8 % in the final bulk solution when added to A or B in the lower conc. and 0,8 or 1,6% when added to the high conc. of A or B.

That makes 48 experiments (+4 repetitive experiments for standard deviation).

Only one response is measured in these experiments (a quality factor 0-100)

I’m familiar with “design of experiments” programs but this time the experiments are already carried out and I don’t know who to get the different components contribution to the results?

Could you give me some ideas how to sent up this program or links to similar problems?
Maybe I can’t use multivariate analysis for this problem?

Looking forward to your responses

 

[GregLocock]

If you look at the theory of how to set the experiments up it is relatively obvious how to analyse it for a given, not necessarily optimal, experimental design.

You may not be able to easily figure out the level of confounding in the higher order interactions, but that is also possible.

The key for analysing them is writing the the experiment out in a rational fashion.

You can use Minitab or Excel to analyse this.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[m777182]

It seems that you have an experiment with three blocks of four factors at two levels : block 1 with A,B,water and x; block 2 with A,B water and Y and block 3 with A,B, water and z, That makes 3x 2^4=48 experiments. For some reasons the experimenter used levels of x,y and z as a function of the levels of A,B and water- probably the response was not significant without it.
m777182

 

[GregLocock]

You end up with a confounded result, but, you suppress the independent contributions, so all you are left with is the combinations that were actually tested.

To be honest this stuff is harder to write about in text than to do in a test-matrix.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.