Archive for May, 2010

PB&J please, but hold the jelly (and margarine) and put it on toast – a mixture design combined with a categorical factor

My colleague Pat Whitcomb just completed the first teach of Advanced Formulations: Combining Mixture & Process Variables.  It inspired me to develop a virtual experiment for optimizing my perfect peanut butter and jelly (PB&J) sandwich.  This was a staple for me and my six siblings when we were growing up.  Unfortunately, so far as I was concerned, my mother generously slathered margarine on the bread (always white in those days – no whole grains) and then thick layers of peanut butter and jelly (always grape).  As you see* in the response surfaces for overall liking [ 🙁 1-9 🙂 ], I prefer that none of the mixture ingredients (A: Peanut butter, B: Margarine, C: Jelly) be mixed, and I like the bread toasted.  This analysis was produced using the Combined design tab from Design-Expert® software version 8 released by Stat-Ease earlier this year.  I’d be happy to provide the data set, especially for anyone that may be hosting me for a PB&J dinner party. 😉

*Click to enlarge the plots so you can see the legend, etc.


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Stat-Ease Corporation celebrates 25 years in business

My business partner Pat Whitcomb started up Stat-Ease as a business entity in 1982,* but he did not incorporate it until June of 1985.  So that brings us to 25 years as a Corporation this coming month.  This is quite an achievement for a software publisher – not many remain since 1985, I’ll wager, especially ones so specialized as us.  That’s our saving grace, I figure – sticking to a niche like a clam in a wave-beaten hollow.

According to this report on U.S. Small Business Administration Office of Advocacy statistics from September 2009, only half of all startups survive five years.  This correlates with a decay curve posted by Scott Shanem Professor of Entrepreneurial Studies at Case Western Reserve University, which shows that only about a quarter of companies remain alive after ten years.

I’d say we’ve done very well to make it this far.  Having weathered the recent economic downturn in good shape, I feel positive about continuing on for at least a few years more. 😉

PS. If you’re interested to learn more about us, check out this history of Stat-Ease.

*The year the word “internet” was used for the first time according to this timeline.  Check out these photos from the 1980’s by the Computer History Museum, especially the Osborne “portable” (24 pounds!) PC with a screen that looks about the size of today’s internet-enabled smart phones.

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Two-level factorial experimentation might make music for my ears

I am a fan of classical music – it soothes my mind and lifts my spirits.  Maybe I’m deluded, but I swear there’s a Mozart effect* on my brain.  However, a big monkey wrench comes flying in on my blissful state when my stereo speaker (always only one of the two) suddenly goes into a hissy fit. I’ve tried a number of things on a hit-or-miss basis and failed to find the culprit.  At this point I think it’s most likely the receiver itself – a Yamaha RX496.  However, before spending the money to replace it, I’d like to rule out a number of other factors:

  1. Speaker set: A vs B
  2. Speaker wire: Thin vs Thick.
  3. Source: CD vs FM-Radio
  4. Speaker: Left vs Right.

It’s very possible that an interaction of two or more factors may be causing the problem, so to cover all bases I need to do all 16 possible combinations (2^4).  But, aside from the work this involves for all the switching around of parts and settings, I am stymied by the failure being so sporadic.

Anyways, I feel better now having vented this to my blog while listening to some soothing Sunday choir music by the Dale Warland Singers on the local classical radio station.  I’m taking no chances: It’s playing on my backup Panasonic SA-EN25 bookshelf system.

*Vastly over-rated according to this report by the Skeptic’s Dictionary.


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Kindergarteners pointing fingers for good (math) or bad (gunning for teacher)

On the one hand, I see this report of a kindergartner suspended for making a gun with his pointer-finger.  That’s discouraging.  But on the other hand, I come across this news from New York Times writer Benedict Carey of a program called “Building Blocks,” developed by the School of Education at the University of Buffalo, that teaches preschoolers fundamental math skills, so when they point a finger, it’s a one, not a gun. 😉

My wife teaches preschool.  She tells me that her kids learn how to count to 100, recognize numbers up to 20, and enumerate physical objects.  In his article on “Building Blocks” Carey refers to this as the “numeric trinity” – crucial to “fuse” kindergarteners for learning math.

Previously educators viewed training on math as being developmentally inappropriate for young children.  This created an inertia that many kids could never overcome.

“ ‘I’m not a math person,’ they say – and pretty soon the school agrees.”

– Doug Clements, Distinguished Professor of Learning and Instruction at State University of New York (SUNY) at Buffalo

But now “research has demonstrated that virtually all young children have the capability to learn and become competent in mathematics.”*  One can only hope that in future kids coming into kindergarten will be pre-charged for math and school in general, so there will be less finger-pointing (gunning) at teachers.

*Source: Description for Mathematics Learning in Early Childhood: Paths Toward Excellence and Equity a report published in July, 2009 by the National Academies Press, which calls for a national initiative to improve mathematics education for preschoolers.  See this press release leading to the full report.

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