Archive for February, 2025
Don’t be a rube—build a snub cube
I am a fan of geometry, but beyond a tetrahedron for mapping out three components in a mixture design of experiment, things get too hyper (pun intended) for me as a practical matter. However, I greatly admire the genius chemists who assembled 12 helical macrocycles into a 2,712-atom polyhedral shape called a snub* cube. These “supramolecules,” the first to made in a stereoselective way—vital to human biology, could lead to crucial advances in pharmaceuticals.
If you are exceedingly interested in geometry, handy with scissors, and desire a very cool ‘sky lantern,’ follow the directions in the video for making a snub cube.
*As you may suspect, “snub” refers to a shape with the corners pushed inwards, similar to one’s ego after suffering from a rejection—some of the air gets taken out of you. ; )
A simple statistic reveals amazing wisdom from crowds
Posted by mark in pop, Uncategorized on February 18, 2025
My good friend Rich Burnham, knowing my interest in off-beat science and stats, drew my attention to this video by YouTuber Michael Stevens (aka “Vsauce”) on an experiment that failed to confirm a phenomenon called the “wisdom of the crowds.”
Normally, as demonstrated by Sir Francis Galton in 1906 from data collected at a country fair on 787 guesses at the weight of an ox,* groups of people exhibit a high level of collective intelligence via a simple median (the “middlemost estimate”)—being off by only 9 pounds for the 1,198 pound ox. This amazes me—blowing away my mindset that the wisdom of a crowd degrades to the ‘lowest common denominator,’ that is, the people with the least knowledge.
Experts agree with Vsauce’s hypothesis that the complete failure of his crowd to correctly guess the number of jelly beans in his jar stemmed from the estimates being shared, rather than gathered with no cross-talk.
“The wisdom of crowds requires that people’s estimates be independent. Studies have found that when people can observe the estimates of others, the accuracy of the crowd typically goes down. People’s errors become correlated or dependent, and are less likely to cancel each other out. We follow our peers, to the detriment of the performance of the group.”
– Psychology professor Tania Lombrozo, No Man Is An Island: The Wisdom Of Deliberating Crowds, posted 3/12/18 by WGCU, a National Public Radio-member station on Florida’s Gulf Coast
I made the same mistake in a 2019 contest for my Anderson clan. While vacationing together at a lakeside resort, I gathered individuals’ estimates on the number of aluminum-can pull-tabs I’d collected for donation to the Ronald McDonald House in Minneapolis. See the picture below of my wife Karen (holding Bertie) working with our oldest grandchild Archer do the count. I asked the participants to write down their guesses on a clipboard by the jar, which created more fun via the gaming aspects of going just above or below a competitor, but violated the statistical requirement for independence.
An interesting workaround that allows collaboration for tapping the “wisdom of the crowds” is to first break the group into a number of teams and then average out their consensus estimates. See the research, based on results from a group of 5,180 people asked to estimate the height of the Eiffel Tower or the like, at this 2018 Letter by Nature Human Behavior on Aggregated knowledge from a small number of debates outperforms the wisdom of large crowds.
To keep things simple, the next time my bottle of pull-tabs fills up for another contest to guess the total, I will go with the simpler approach for crowd wisdom by banning cross talk and then seeing if the median estimate wins. If it doesn’t work, I will blame it on our family group being too small (though it does exceed 20—all in one cabin!).
An homage to an engineer extraordinaire—my dad
Posted by mark in engineering on February 3, 2025
James J. (Jim) Anderson, my dad (seen pictured in 1990 with former President Gerald Ford), passed away peacefully on Wednesday, January 29, at the age of 95 after being hit hard by influenza A (be careful out there—it’s spiking now across the USA). Both of us being engineers, him inspired by his dad—an engineer also, and me by him, we enjoyed many great talks in his later years about technical matters along the lines of this StatsMadeEasy blog. This is my homage to Jim’s engineering accomplishments, mostly based on what I gathered from his stories (which I will greatly miss) and my memories, thus off a bit on some of the particulars, but fairly accurate, hopefully. It’s quite a story!
Jim was a stellar masters civil engineer who specialized in wastewater treatment before the realization of the damage being wreaked on our rivers by unconstrained dumping. His first job after achieving his bachelor’s degree in sanitary engineering in 1952—a newly created specialty at University of Minnesota—was a demonstration project for The American Meat Institute aimed at cleaning up waste streams from the Hormel plant in Austin, Minnesota (where I was born in 1953). He then moved us (by then my sister Nancy also) to the Twin Cities for a job at Toltz, King, Duvall, Anderson, and Associates (now known as TKDA), being assigned as City Engineer for West Saint Paul.
Jim then took an engineering job at the aptly named Pigs Eye Wastewater Treatment Plant in Saint Paul. While there he became skeptical of sketchy studies dating back to the 1930s that led to heavy use of flocculants at a substantial ongoing cost. This seemed to produce little effect, but Jim knew it would take a definitive experiment to overcome the ‘common knowledge’ of its efficacy. Someone suggested that a fellow at University of Wisconsin by the name of George Box might provide some help on the design of experiments (DOE). Sure enough, the DOE designed by Box did the trick—no more wasteful use of chemicals after that.
In 1968, Jim completed his master’s thesis, which involved regression modeling—a tool undergoing rapid development at that time. He had to defend the methodology against a professor who doubted anything produced by a computer could ever be relied upon.
About then, Jim was at the right place at the right time by submitting a proposal to the Federal Water Pollution Control Administration (created in 1965 by the Clean Water Act) for ways to deal with secondary sewage—the surge of dirty water pouring through single-pipe systems in Saint Paul and many other cities after heavy rains. To his surprise, a grant came through in an amount that seemed overwhelmingly large at the time—$1,741,000.* Even more surprisingly his engineering manager went for it. Predictive modeling of rainfall based on regression was the key to Jim’s solution for dealing with overflow. Knowledge was power. Being able to anticipate the surges, weirs (small mechanical barriers inside the sewage pipe) and inflatable dams trapped the water long enough to then be released in a volume that would not overwhelm the wastewater treatment plant.
Other cities jumped on his solutions, starting with Cleveland, infamous for their 1969 Cuyahoga River fire. Jim then started a consulting firm called Watermation, which did a lot of good for major cities worldwide. The timing again was ideal due to the rapid development of computing power, such as the Digital Equipment Corporation (DEC) PDP-8 used by Jim and his team—the same machine that got Bill Gates going on Microsoft.
That’s enough to provide the gist of what Jim did that fascinated me from an early age and still amazes me as a chemical process development engineer and fan of stats and computers. Not only was he a great mind, Dad could do anything hands on—welding, wiring, soldering (a whiz at fixing TV’s and radios), plumbing, woodworking, etc. He brought me and my younger six siblings up to Saint Paul YMCA’s Camp DuNord for many years. Naturally when the time came to put up outhouses, he got volunteered. ; ) On of my proudest memories was Dad winning a contest for log splitting by cutting it in 4 parts with two chops—the advantage of being an engineer (and handy with an ax).
By the way, though a bit too young to serve in World War II, Jim graduated from training in Pensacola, Florida as a Naval Aviator before being honorably discharged in early 1949 due to reductions in the armed forces at the time. His service falls within the window of WWII vets, thus I feel that all-in-all he deserves consideration as an honorable member of the Greatest Generation. I can certainly say there will never be another individual of the caliber of James Joseph Anderson.
*Page down the Selected Urban Storm Water Runoff Abstracts, Second Quarterly Issue for #048 Interim Report to the Federal Water Pollution Control Administration on an May 1969 interim report on this demonstration project.
PS: A few more of Jim’s engineering achievements that I gleaned from searching the internet (probably not comprehensive):
- Publication of “Remote Control of Combined Sewer Overflows” (co-authored by his colleague Robert L. Callery) in the Journal of the Water Pollution Control Federation, Vol. 46, No. 11 (Nov., 1974), pp. 2555-2564 (10 pages)—see the abstract for some very impressive statistics on reduction of pollution due to work by him and Watermation.
- Him speaking on “Present Practice and Research Needs in Wastewater Collection System Design and Operation” for a workshop in 1975 sponsored by the EPA.
- US Patent 4,168,233 for an “Automatic activated sludge control system” (published 9/18/1979)