|
|
|
An Essential Primer on Full and Fractional Factorial Test Design
Even if you are using full factorial to get the same amount of information as a fractional factorial test, it will take more time since you need more data to see statistically relevant differences between the many experiments. You might be wondering how fractional factorial can be accurate if interactions are possible?
Random interactions of high relevance are very rare, especially when looking for interactions of more than 2 factors. You really need to design tests where you look for meaningful interactions that are based on true business requirements rather than hoping for a random and low influence interaction between a red button, a hero shot and a headline.
I am a fan of design of experiments as long time readers know (see posts on design of experiments).
Some good resources for more on the topics discussed above: What Can You Find Out From 8 and 16 Experimental Runs? by George Box - Statistics for Experimenters - Design of Experiments in Advertising.
Related: Google Website Optimizer - factorial experiment articles - Using Design of Experiments - Marketers Are Embracing Statistical Design of Experiments
MEMS development in less than half the time by Christopher N. Delametter, Eastman Kodak Company
Related: Design of Experiments articles - Using Design of Experiments - Statistics for Experimenters - Why Use Designed Factorial Experiments? - Kodak Debuts Printers With Inexpensive Cartridges
Please submit your favorite management posts to the carnival. Read the previous management carnivals.
Marketers Are Embracing Statistical Design of Experiments (site broke link so I removed it) by Richard Burnham.
For more on Design of Experiments see:
The classic Statistics for Experimenters has been updated by George Box and Stu Hunter, two of the three original authors. Bill Hunter, who was my father, and the other author, died in 1986. Order online: Statistics for Experimenters: Design, Innovation, and Discovery , 2nd Edition by George E. P. Box, J. Stuart Hunter, William G. Hunter.
I happen to agree with those who call this book a classic, however, I am obviously biased.
Google Scholar citations for the first edition of Statistics for Experimenters.
Citations in Cite Seer to the first edition.
The first edition includes the text of Experiment by Cole Porter. In 1978 finding a recording of this song was next to impossible. Now Experiment can be heard on the De-Lovely soundtrack.
Text from the publisher on the 2nd Edition:
Rewritten and updated, this new edition of Statistics for Experimenters adopts the same approaches as the landmark First Edition by teaching with examples, readily understood graphics, and the appropriate use of computers. Catalyzing innovation, problem solving, and discovery, the Second Edition provides experimenters with the scientific and statistical tools needed to maximize the knowledge gained from research data, illustrating how these tools may best be utilized during all stages of the investigative process. The authors’ practical approach starts with a problem that needs to be solved and then examines the appropriate statistical methods of design and analysis.
(more…)
Originally posted to the Deming Electronic Network, 22 Sep 1999, in reponse to this message
I would like to say that I think it is good that we have disagreements on the DEN. I think it is a strength of the DEN, not a weakness. However, I think we sometimes get to personal with no real purpose. One example of this, for me, is: “Well, I guess we knew different Demings. Mine was a teacher named Dr. W. Edwards Deming.” I doubt this statement is meant to be taken literally, and if it is not I do not see what it adds to the discussion. I point this out not because I think this is some bad act that should be punished but that I think we need to continue to develop a sense of how we wish to express our disagreements and I think that we should try to do so more constructively.
I find this statement so far from the truth that it would seriously damage any PDSA with this as an accepted assessment of history. I do not believe Deming had such an inaccurate view (of course I may be wrong). I do believe we need to improve our practice of Quality (and to do that we need to understand what happened in the past and why it was not more successful). The idea that Design of Experiments (DoE) was at the core of some Quality Movement to me is not at all accurate. (more…)
Curious Cat Management Improvement Blog © curiouscat.com 2005-2008 powered by WordPress