Issue: Volume 8, Number 7
Date: July 2008
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

For an assortment of appetizers to get this Alert off to a good start, see these new blogs at (beginning with the most recent one):

— Inverse transformation puts mileage comparisons on track
— Origin of 3.2% alcohol beer — an antidote for those dispirited by the Great Experiment
— Duck named DOE (pronounced "dewie")
— Brains for beer
— Sign for physics students still unclear on the concepts

(Correction to June FAQ Alert — John Hunter, the author of my fav blog — "Curious Cat", is the son of the revered DOE expert Bill, one of the two unrelated Hunters (the other is Stu) who co-authored the landmark text "Statistics for Experimenters with George Box.)

Topics in the body text of this DOE FAQ Alert are headlined below. Given a plenitude of things worth alerting you too, I slacked off on FAQs and their answers. My excuse is taking some summer vacation that coincides with celebrating Independence. (Do you suppose I am referring to the separation of the United States from England; or could it be that I am celebrating the statistical assumption that one observation be independent of every other? Flip a coin!)

1. Released: Version 7.1.5 of Stat-Ease software for DOE
2. Newsletter Alert: July issue of the Stat-Teaser features my story of "How DOE Saved My Life and Made it Worth Living"
3. Workshop Alert: "Designed Experiments for the Life Sciences"
4. Webinar Alerts:
*-> "Dual Response Surface Methods (RSM) to Make Processes More Robust" (encore by popular demand)
*-> "Best ‘Pat-Tricks’ on Model Diagnostics"
5. Webinar Comments: Measuring variation as a dual response
6. Book Giveaway: Winners announced
7. Course Alert: Intro to optimal DOE by Peter Goos in Belgium

P.S. Quote for the month: Humorous observation by the late George Carlin on the widespread disrespect for people who do well with math. (Page through to the end of this e-mail to enjoy the actual quote.)


1. Released: Version 7.1.5 of Stat-Ease software

Free, fully-functional downloads of Design-Ease® and Design-Expert® software, both now at version 7.1.5, are posted at for evaluation. This web site also provides free patches to update older, licensed, versions of 7.1. The new release primarily addresses maintenance issues. View the ReadMe file for installation tips, known 'bugs,' change history, and FAQs.


2. Newsletter Alert: July issue of the Stat-Teaser features my story of "How DOE Saved My Life and Made it Worth Living"

Many of you will soon receive 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 I dramatically titled "How DOE Saved My Life and Made it Worth Living." You may find it interesting. Also, this issue of Stat-Teaser announces a new class on Designed Experiments for Life Sciences. Read all about it! This issue also provides a heads-up to the StatsMadeEasy blog, which I write for my amusement and perhaps others who enjoy my musings into issues of statistics and sidetracks from there. Go back to the beginning of this DOE FAQ Alert to see the latest crop of blog.

Thank you for reading our Stat-Teaser newsletter. If you do 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. However, we do appreciate you passing around hard copies of the Stat-Teaser, so do not feel obliged to forego this.


3. Workshop Alert: Designed Experiments for the Life Sciences

Stat-Ease debuts Designed Experiments for Life Sciences (DELS) on August 5-7 at its training center in Minneapolis. Developed by popular demand, this three-day workshop demonstrates the application of DOE for the benefit of scientists, engineers, and technical professionals working in the pharmaceutical, biomedical technology and biomedical device fields, as well as organizations and institutions that devote the majority of their efforts to research, development, technology transfer, or commercialization of these fields. Seats will fill fast for this inaugural DELS, and (based on surging demand we've been experiencing) the following DOE classes coming up on our training schedule. If possible, enroll at least four 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!

—> Designed Experiments for Life Sciences (DELS)
(Detailed at
> August 5-7 (Minneapolis, MN)

—> Experiment Design Made Easy (EDME)
> August 19-21 (Minneapolis)

—> Mixture Design for Optimal Formulations (MIX)
> July 29-31 (Minneapolis)

—> Response Surface Methods for Process Optimization (RSM)
> September 23-25 (Minneapolis)

—> DOE for DFSS: Variation by Design (DDFSS)
> November 11-12 (Minneapolis)

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


4. Webinar Alerts:
-> "Dual Response Surface Methods (RSM) to Make Processes More Robust" (encore by popular demand)
-> "Best ‘Pat-Tricks’ on Model Diagnostics"

You are invited to attend a free web conference by Stat-Ease on "Dual Response Surface Methods (RSM) to Make Processes More Robust" on Tuesday, July 15 at 8 AM, USA Central Daylight Time (CDT), which is 13:00 in Coordinated Universal Time (UTC). (We are at UTC -5 under CDT.) This talk is an encore that I am presenting on request from some folks who were out the week of my initial round of webinars — a time when many US manufacturers go down for annual maintenance.

The next regularly scheduled Stat-Ease webinar will be presented by Consultant Pat Whitcomb who will offer up his "Best ‘Pat-Tricks’ on Model Diagnostics (What are they? Why use them? What good do they do?)." This free conference, which Pat will keep at an intermediate level statistically, will be broadcast on Tuesday, August 12 at 8 AM USA CDT (13:00 UTC). It will be offered again at 8 PM that evening (01:00 UTC August 13 — Wednesday) and one more time the following day at 12 PM noon (17:00 UTC August 13).

When developing these one-hour educational sessions, our presenters often draw valuable material from Stat-Ease DOE workshops. Attendance may be limited, so sign up as soon as you see your way clear by contacting our Communications Specialist, Karen, via If you can be accommodated, she will send you the link for the WebConnect and dial-in for ConferenceNow voice via telephone (toll-free access extends worldwide, but not to all countries).


5. Webinar Comments: Measuring variation as a dual response

Re: "Dual Response Surface Methods (RSM) to Make Processes More Robust" — posted at the Stat-Ease webinar announcement site:

-----Original Comments-----
From: "Friendly, neighborhood statistician" Arved Harding, Eastman Chemical, Tennessee

"Standard Deviation will just be the measurement error unless you repeat the runs. It depends on the process:
— Imagine a polymer process where a run last 8 hours and it takes 4 hours to level off so we take hourly samples at hours 4,5,6,7 and 8. We can get the average and standard deviation of these.
— Imagine coating a metal panel and measuring color or thickness at many places on the panel. Maybe even a 9x9 grid of 81 measurements per panel. This makes for a good use of the standard deviation as a response which includes test noise but also uniformity of application of the coating.
— As a third example imagine an injection process with a 72 cavity mold. Let’s imagine for each run we plan to do 2 shots to clean out the mold then will collect 10 more shots. This gives us 720 possible parts to measure per run. You might want to measure parts from 10 random cavities per shot for 3 shots. Or some other sampling scheme, depending on your knowledge of the sources of variation. Thanks again for the great webinar."

In the semiconductor manufacturing case (by Doug Montgomery, et al) that I detailed for dual response RSM, individual wafers from an etching process were picked out at random from 11 batches by day made at each run of a central composite design. The primary attribute of each was then measured and the mean and standard deviation collected for response modeling. Conditions were discovered that produced product on target with a minimum of variability caused batch-by-batch. It is good of Arved to suggest other possibilities.


6. Book Giveaway: Winners announced

In last month's DOE FAQ Alert, I announced a drawing for three copies of "Engineering Statistics, 3rd Ed" by Montgomery, Runger, Hubele — originally priced at $150. (Sorry, due to the high cost of shipping, this offer applied only to residents of the United States and Canada.) These lucky readers were drawn at random from 53 entrants:
-> Robert Russell, Fuels R&D Director, Oryxe Energy International, California
-> Cal Hoople, Quality Engineer, Coloplast, Minnesota
-> Larry Acquarulo, President, Foster Corp., Connecticut
Congratulations to you three and condolences to the others who entered into this drawing. Keep watching for more great books to be given away in future.

(Learn more about engineering statistics by attending the two-day computer-intensive [Microsoft Excel] workshop "Statistics for Technical Professionals." For a description of this class — offered on-site only, see For more information, call Elicia at 612.746.2038.)


7. Course Alert: Intro to optimal DOE by Peter Goos in Belgium

-----Original Announcement-----
"On September 15 and 16, I will again teach an introductory course on optimal design of experiments at the Faculty of Applied Economics of the University of Antwerp (Belgium). The target audience for the course is starting Ph.D. students and anyone else who would like a primer on optimal design. Prerequisites for the course are knowledge of basic statistics and regression analysis. Familiarity with classical design of experiments is not required. The course will start with an intuitive introduction of the topic and will gradually build up to more complicated situations. The attention will not be restricted to optimal design for linear regression models, but Bayesian optimal design and minimax designs for nonlinear regression models will also be discussed. The strengths and weaknesses of optimal design will be illustrated, and some remedies to overcome some of the problems will be given.

The venue for the course is in the Antwerp city center. The Antwerp city center is easy to reach by train, and there is an hourly bus service from and to Brussels National Airport. Details about registration can be found at

Please feel free to forward this message to anyone who might be interested in the course. Kind regards, Peter Goos"

Stat-Ease sent two programmers, one of them my son Hank, and a statistician to a course by Peter last March in Antwerp. They came away with many good ideas on optimal design.


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. Humorous observation by the late George Carlin on the widespread disrespect for people who do well with math:

"People love to admit they can't do math. But they will never admit to having a poor sense of humor."
—George Carlin.

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, especially Tryg Helseth and Neal Vaughn (
—Heidi Hansel, Stat-Ease marketing director, and all the remaining staff


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 (see above)

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