5.
Process Improvement
5.3. Choosing an experimental design 5.3.3. How do you select an experimental design? 5.3.3.4. Fractional factorial designs


Useful fractional factorial designs for up to 10 factors are summarized here  There are very useful summaries of twolevel fractional factorial designs for up to 11 factors, originally published in the book Statistics for Experimenters by G.E.P. Box, W.G. Hunter, and J.S. Hunter (New York, John Wiley & Sons, 1978) and also given in the book Design and Analysis of Experiments, 5th edition by Douglas C. Montgomery (New York, John Wiley & Sons, 2000).  
Generator column notation can use either numbers or letters for the factor columns 
They differ in the notation for the
design generators. Box, Hunter,
and Hunter use numbers (as we did in our
earlier discussion) and Montgomery
uses capital letters according to the following scheme:


Details of the design generators, the defining relation, the confounding structure, and the design matrix 
TABLE 3.17 catalogs these useful fractional factorial designs using
the notation previously described in FIGURE
3.7.
Clicking on the \( 2_{R}^{kp} \) specification for a given design provides details (courtesy of Dataplot files) of the design generators, the defining relation, the confounding structure (as far as main effects and twolevel interactions are concerned), and the design matrix. The notation used follows our previous labeling of factors with numbers, not letters. 

Click on the design specification in the table below and a text file with details about the design can be viewed or saved 
