Issue: Volume 9, Number 10
Date: October 2009
From: Mark J. Anderson, Stat-Ease, Inc., Statistics Made Easy® Blog

Dear Experimenter,

Here's another set of frequently asked questions (FAQs) about doing design of experiments (DOE), plus alerts to timely information and free software updates. If you missed the previous DOE FAQ Alert, see below.

==> Tip: Get immediate answers to questions about DOE via the Search feature on the main menu of the Stat-Ease® web site. This not only pores over previous alerts, but also the wealth of technical publications posted throughout the site.

Feel free to forward this newsletter to your colleagues. They can subscribe by going to If this newsletter prompts you to ask your own questions about DOE, please address them via mail to:

For an assortment of appetizers to get this Alert off to a good start, follow this link,* (-> new web site!), and see a number of new blogs (listed below, beginning with the most recent one):

—Digging into numbers to the last vigintillionth of a yoctometer
—An ideal world: Ballpark beer cost correlated completely with quality of baseball
—Math messed with future astronaut’s mind and made him think faster
—Fair food follies—sticking on calories at a prodigious rate

"Your StatsMadeEasy blogs brighten up a dreary workday!"
—Applied Statistician, Florida

*Need a feed or e-mail updates from StatsMadeEasy? Go to It's easy!

Topics in the body text of this DOE FAQ Alert are headlined below (the "Expert" ones, if any, delve into statistical details).

1. Newsletter Alert: September issue of the Stat-Teaser features mixture design for maximizing flights of film-canister rockets
2. FAQ: How do I detect strange results?
3. Info Alert: RSM for pharmaceutical quality by design (QbD)
4. Job Opening : Help wanted—a DOE-savvy technical professional with chemical, biological or biochem background
5. Events Alert: Check out these unique opportunities to learn first-hand about DOE
6. Workshop Alert: See when and where to learn about DOE
7. Survey: What is your preference on days for 2-day workshops?

P.S. Quote for the month: Do math and stats really cause one to miss the forest for the trees or the galaxy for the stars? See two views—con and pro.


1. Newsletter Alert: September issue of the Stat-Teaser features mixture design for maximizing flights of film-canister rockets

Many of you have received, or soon will, a printed copy of the latest Stat-Teaser, but others, by choice or because you reside outside of North America, will get your only view of the September issue at It features an article by me that details a rocket-science experiment aimed at optimizing the concentration of Alka-Seltzer®. With capricious assistance from my youngest daughter and the magic of mixture DOE, I managed to blow a film canister up to rooftop heights. This Stat-Teaser also features an educational article by Consultant Shari Kraber on "Over-Selection of Effects on the Half-Normal Plot." If you make use of two-level factorial design (or provide statistical advice to the experimenters), I urge you to read Shari's advice on picking effects from the handy half-normal graph.

Thank you for reading our Stat-Teaser newsletter. If you get the hard copy, but find it just as convenient to read what we post to the Internet, consider contacting us to be taken off our mailing list, thus conserving resources. (Note: You will be notified via the DOE FAQ Alert on new newsletter posts.) In any case, we appreciate you passing along hard copies and/or the link for the posting of the Stat-Teaser to your colleagues.


2. FAQ: How do I detect strange results?

-----Original Question-----
A chemist
"I was trying to analyze results from a recent design and I can't seem to make any sense of it. Just looking at the data it seems that there are some 'strange' results that don't fit. Is there an easy way for the software to pick these out?"

Answer (from Stat-Ease Consultant Wayne Adams):
"The diagnostic plots can be used to find outliers and influential points after a model has been fit. Another place to 'see' the data points is under the graphs columns node. Using a mouse or other pointing device to draw a box around suspect points will highlight them, turning them italic and blue in the design layout."

The externally studentized (also know as "outlier t") plot is a good place to look for outliers. See this detailed in an article co-authored by me on "How to Use Graphs to Diagnose and Deal with Bad Experimental Data," which you will find posted at

(Learn more about assessing outliers by attending the computer-intensive workshop "Experiment Design Made Easy." See for a description of this class and link from this page to the course outline and schedule. Then, if you like, enroll online.)


3. Info Alert: RSM for pharmaceutical quality by design (QbD)

See in this article by PharmaQbD (QbD = Quality by Design) how Sarah Betterman, Scientist for Upsher-Smith, made use of a Box-Behnken design, a response surface method (RSM*), to determine how key fluidized-bed coating parameters affected dissolution of their pharmaceutical product:

If you are interested in publishing your DOE story, please contact Heidi via or call her 612.746.2033. See our current collection of DOE case studies and articles at We are especially in need of applications from the life sciences. Factor details can be coded for secrecy sake, so confidentiality need not be compromised.

*(Learn more about RSM by attending the three-day computer-intensive workshop "Response Surface Methods for Process Optimization." See for a complete description. Link from this page to the course outline and schedule. Then, if you like, enroll online.)


4. Job Opening: Help wanted—a DOE-savvy technical professional with chemical, biological or biochem background

Stat-Ease, Inc, a Minneapolis-based DOE software, training and consulting company, has a permanent, full-time opportunity for an energetic person to join our team. The position is a combination of teaching and technical development of materials and software ideas. Job responsibilities include teaching design of experiments workshops, providing statistical support to clients, working with programmers to implement new features, defining test cases for statistical software development, writing/editing technical materials, and other duties based on experience. This is a permanent, full-time position located in Minneapolis with approximately 25% travel.

Required qualifications:
- Chemical , Biological, or related Engineering degree with 2-8 years experience
- Ability to 'speak the language' of chemical engineers and other technical professionals in the chemical, coatings, pharmaceutical or biological areas
- Strong math skills, MS Applied Stat nice to have
- Aptitude and desire to learn more about how statistics can improve products and processes
- Hands-on DOE experience, mixture design desirable
- Teaching experience and strong ability to communicate with technical professionals
- Excellent English skills, verbal and written
- Ability to travel at least 1 week per month, some internationally
- US Citizenship required

Resumes should be e-mailed to


5. Events Alert: Check out these unique opportunities to learn first-hand about DOE

(2nd Notice) Introduction to Experimental Design & AAO FX Software is a 3-1/2 day course designed to provide assay developers with a foundation in statistical design of experiments (DOE) and the use of Automated Assay Optimization (AAO) FX software to apply DOE using the Beckman Coulter Biomek® FX Laboratory Automation Workstation. Design-Expert software is used to setup your assay DOE; Automated Assay Optimization (AAO) FX software is used to translate your DOE into corresponding Biomek® FX methods and finally, the assay results are analyzed using Design-Expert software. This course will be presented on October 19-22 in Brea, CA by Pat Whitcomb (Stat-Ease) and Lisa Fan (Beckman Coulter). Click for more details.

I will present a webinar on DOE to the ASQ Lafayette (Indiana) Sectional Meeting on October 20, 2009.* I am also planning to join Stat-Ease Marketing Director Heidi Hansel Wolfe at the MD&M (Medical Device and Manufacturing) conference in Minneapolis on October 21-22. We will be in booth 635.

Click for a list of upcoming appearances by Stat-Ease professionals. We hope to see you sometime in the near future!

*Do you need a speaker on DOE for a learning session within your company or technical society at regional, national, or even international levels? If so, contact me. It may not cost you anything if Stat-Ease has a consultant close by, or if a web conference will be suitable. However, for presentations involving travel, we appreciate reimbursements for airfare, hotel and meals—expenses only. In any case, it never hurts to ask Stat-Ease for a speaker on this topic.


6. Workshop Alert: See when and where to learn about DOE

Seats are filling fast for the following DOE classes. If possible, enroll at least 4 weeks prior to the date so your place can be assured. However, do not hesitate to ask whether seats remain on classes that are fast approaching!

—> Experiment Design Made Easy (EDME)
(Detailed at
> November 3-4* (Minneapolis, MN)

—> Mixture Design for Optimal Formulations (MIX)
> October 27-28* (Minneapolis)

—> Response Surface Methods for Process Optimization (RSM)
> December 1-2* (Minneapolis)

—> Designed Experiments for Life Sciences (DELS)
> November 10-11 (Cambridge, MA)

*Now condensed to two days (formerly a three-day workshop)

See for complete schedule and site information on all Stat-Ease workshops open to the public. To enroll, click the "register online" link on our web site or call Elicia at 612.746.2038. If spots remain available, bring along several colleagues and take advantage of quantity discounts in tuition. Or, consider bringing in an expert from Stat-Ease to teach a private class at your site.**

**Once you achieve a critical mass of about 6 students, it becomes very economical to sponsor a private workshop, which is most convenient and effective for your staff. For a quote, e-mail


7. Survey: What is your preference on days for 2-day workshops?

Our Workshop Coordinator Elicia needs input from those of you who are prospective workshop students or sponsors (statisticians and managers encouraging experimenters to learn DOE). We recently shifted to a two-day format to deliver training more concisely, as demanded in these fast-paced times. Due to the need for maximizing utilization of computer classrooms,* these workshops must be held either at the beginning or the end of the work week. Which do you prefer for class days:
- Monday-Tuesday, or
- Thursday-Friday?

Please e-mail with your preference.

*Note: This restriction does not apply to workshops held at the Stat-Ease training facility in Minneapolis — only ones held elsewhere around the country.


I hope you learned something from this issue. Address your general questions and comments to me at:




Mark J. Anderson, PE, CQE
Principal, Stat-Ease, Inc. (
2021 East Hennepin Avenue, Suite 480
Minneapolis, Minnesota 55413 USA

PS. Quote for the month—Do math and stats really cause one to miss the forest for the trees?:

A negative view on "the curse of knowledge":
"I find mathematics and statistics 'challenging'. This has saved me from important errors of thinking.

—Robert Skidelsky, author of "Keynes: The Return of the Master—The Old Economist, Relevant Amid the Rubble". See for a review by the New York Times..

A lyrical counter-view:
"In life
Some mock me for doing statistics
Some loathe me and statistics
Some don't understand what statistics are
Why is it that statistics
Put a calm smile on my face?
Because of statistics I can solve the deepest mysteries
Because of statistics I will not be lonely again playing in the data
Because of statistics I can rearrange the stars in the skies above
Wang Jiaowei, Maidian, China Statistics Station

Trademarks: Stat-Ease, Design-Ease, Design-Expert and Statistics Made Easy are registered trademarks of Stat-Ease, Inc.

Acknowledgements to contributors:
—Students of Stat-Ease training and users of Stat-Ease software
—Stat-Ease consultants Pat Whitcomb, Shari Kraber and Wayne Adams (see for resumes)
—Statistical advisor to Stat-Ease: Dr. Gary Oehlert (
—Stat-Ease programmers, led by Neal Vaughn and Tryg Helseth (
—Heidi Hansel Wolfe, Stat-Ease sales and marketing director, and all the remaining staff that provide such supreme support!


Interested in previous FAQ DOE Alert e-mail newsletters?
To view a past issue, choose it below.

#1 Mar 01, #2 Apr 01, #3 May 01, #4 Jun 01, #5 Jul 01 , #6 Aug 01, #7 Sep 01, #8 Oct 01, #9 Nov 01, #10 Dec 01, #2-1 Jan 02, #2-2 Feb 02, #2-3 Mar 02, #2-4 Apr 02, #2-5 May 02, #2-6 Jun 02, #2-7 Jul 02, #2-8 Aug 02, #2-9 Sep 02, #2-10 Oct 02, #2-11 Nov 02, #2-12 Dec 02, #3-1 Jan 03, #3-2 Feb 03, #3-3 Mar 03, #3-4 Apr 03, #3-5 May 03, #3-6 Jun 03, #3-7 Jul 03, #3-8 Aug 03, #3-9 Sep 03 #3-10 Oct 03, #3-11 Nov 03, #3-12 Dec 03, #4-1 Jan 04, #4-2 Feb 04, #4-3 Mar 04, #4-4 Apr 04, #4-5 May 04, #4-6 Jun 04, #4-7 Jul 04, #4-8 Aug 04, #4-9 Sep 04, #4-10 Oct 04, #4-11 Nov 04, #4-12 Dec 04, #5-1 Jan 05, #5-2 Feb 05, #5-3 Mar 05, #5-4 Apr 05, #5-5 May 05, #5-6 Jun 05, #5-7 Jul 05, #5-8 Aug 05, #5-9 Sep 05, #5-10 Oct 05, #5-11 Nov 05, #5-12 Dec 05, #6-01 Jan 06, #6-02 Feb 06, #6-03 Mar 06, #6-4 Apr 06, #6-5 May 06, #6-6 Jun 06, #6-7 Jul 06, #6-8 Aug 06, #6-9 Sep 06, #6-10 Oct 06, #6-11 Nov 06, #6-12 Dec 06, #7-1 Jan 07, #7-2 Feb 07, #7-3 Mar 07, #7-4 Apr 07, #7-5 May 07, #7-6 Jun 07, #7-7 Jul 07, #7-8 Aug 07, #7-9 Sep 07, #7-10 Oct 07, #7-11 Nov 07, #7-12 Dec 07, #8-1 Jan 08, #8-2 Feb 08, #8-3 Mar 08, #8-4 Apr 08, #8-5 May 08, #8-6 June 08, #8-7 July 08, #8-8 Aug 08, #8-9 Sep 08, #8-10 Oct 08, #8-11 Nov 08, #8-12 Dec 08, #9-01 Jan 09, #9-02 Feb 09, #9-03 Mar 09, #9-04 Apr 09, #9-05 May 09, #9-06 June 09, #9-07 July 09, #9-08 Aug 09, #9-09 Sep 09, #9-10 Oct 09 (see above)

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