Distance learning vs in-person training—pros and cons
Posted by mark in Education, Uncategorized on January 7, 2025
In March of 2020 when the Covid-19 pandemic came to a head with widespread quarantines, the Stat-Ease training team quickly Zoomed (pun intended) our workshops from in-person (IP) to distance learning (DL). It went amazingly well from the start.
Coincidentally, two of my grandchildren shifted from IP grade-school to DL at our home. The youngest, a kindergartner (Laine), benefited greatly by the oversight of my wife Karen—a retired preschool teacher. I helped the other (Archer), a third grader. It did not start well due to many technical difficulties and troublesome adjustments for teachers and students. We continued our DL home schooling the following school year due to the ongoing quarantine in Minnesota. By the time IP classes resumed, the DL went about as well as could be expected—the most difficult class being physical education, especially in the winter due to our home lacking a gym.
This unplanned experiment on DL across the range of child versus adult revealed a big interaction effect due to the age of the learners—IP being best for grade schoolers and DL being a very viable alternative for mature students. A few weeks ago, I got reinforcement for this observation when teaching cribbage IP as a volunteer to Laine—now in 4th grade—and two of her classmates. This would have been far harder DL.
The reason I’m bringing all this up is that my colleague Shari Kraber, who retired as our workshop manager but continues to provide training, asserts that “in-person training is not as ideal educationally and that the retention of the materials is BETTER using distance learning.”* I’m also a big fan of DL—far easier for me to teach from my home offices in my summer or my winter home (or on the road between). Google’s AI (Gemini) says that there’s no definitive answer on IP vs DL, and that the biggest factor is quality of the teaching and the materials, which makes a lot of sense to me.
Rachel Poleke, our current workshop manager, suggests that another big factor is the preference of individual students for IP versus DL. I totally agree: Ideally the delivery would be tailored to each student. This being impractical, Stat-Ease instead offers on a class-wide basis to deliver private training either way, depending on the preference of our client. For example, one year ago last September I traveled to Netherlands to teach a DOE workshop for a client headquartered in Leiden’s Bio Science Park. That was fun and very gratifying for the great response. It’s nice to take a break from Dl, benefitting by much stronger feedback from students (e.g., the ‘deer in the headlights’ look when clueless) and the ability to watch them work through case studies (our workshops are computer intensive).
Stat-Ease plans to present a rare IP public workshop—Modern DOE for Medical Devices—at our Minneapolis headquarters this year. This brings a huge advantage of DL training immediately to mind: Anyone from anywhere in the world can Zoom in, thus making it far easier for us to achieve a critical mass for class.
One thing I can say for sure—it’s great to have such a viable option for DL nowadays. When I first began working as a trainer of quality-engineering tools in the 1970’s, the technology for DL existed (e.g., PLATO) but, being pre-Internet and all, it could not compete with IP.
It will be interesting to see how things settle out in coming years for IP versus DL, both for corporate training and schooling at primary and secondary levels. Hopefully, the quality of education (based on subjective measures!) will not be lost in the shuffle of convenience for scheduling and the relative costs.
*1/1/25 Stat-Ease blog Ask An Expert: Shari Kraber
Keep your black plastic spatulas for math-challenged scientists
Back in my day, when a boy misbehaved, he would be threatened with “The Paddle” being administered to his back side. I don’t advocate going back to this corporal punishment. However, with the news that scientists raising the alarm about a dangerous fire retardant in black plastic spatulas miscalculated 60 times 7,000 to a product of 42,000—off by a factor of 10,* I think these less fearsome implements could be repurposed to gently tap some math sense into their heads.
As you can see pictured, I found one, very old, black plastic spatula (classic KitchenAid!) in our kitchen utensil drawer, which I will retire from service but retain as a Halloween decoration or donate to the cause of math ‘education.’
*That viral black plastic kitchen utensil study was overblown thanks to a simple math mistake , Mashable, Tim Marcin, December 16, 2024.
Colors to dye for
Posted by mark in food science, Uncategorized on December 4, 2024
I grew up in the golden age for kids’ cereals, first with Trix from General Mills—introduced in 1954 in three colors: raspberry red, orangey orange and lemony yellow (now also wildberry blue, grapity purple and watermelon), followed in 1963 with Froot Loops from Kellog—also in red, orange and yellow—Toucan Sam style (now also green, blue and purple). Back then nobody worried much about how these manufacturers colored their cereals—artificially or otherwise. However, nowadays a consensus has built up about a “rainbow of risks” caused by synthetic food dyes. Political pressure across the spectrum from Gavin Newsome to Robert F Kennedy, Jr continues to build for banning these presumably harmful additives.
This sets the stage for some interesting history by American Heritage magazine on letting the food industry “poison” us as RFK, Jr puts it. Their Senior Editor Bruce Watson reported in the November/December issue how “many of our first food-safety laws arose after healthy young volunteers became sick when they tried commercial foods containing toxic additives.” These daredevils comprised “The Poison Squad” created in 1902 by Harvey Wiley Washington—who became known as the “Father of the Pure Food and Drugs Act” when it became law in 1906.
“NONE BUT THE BRAVE CAN EAT THE FARE.”
– Sign posted outside the Department of Agriculture building to enlist human ‘guinea pigs’
As historian Deborah Blum noted in her book The Poison Squad: One Chemist’s Single-Minded Crusade for Food Safety at the Turn of the Twentieth Century Washington deserves credit for “one of the most significant experiments in the 20th century.” For example, just prior to his crusading work, hundreds or perhaps thousands of children died from milk “embalmed” with formaldehyde.
Not to lessen the current concern over artificial dyes, we can be thankful for the relative safety of our food compared to the fare in the early 1900s. But I do not advocate going back to the days when potential poisons were tested on human subjects. Though I suppose there’s worse things than being tasked with eating large quantities of Trix and Froot Loops, provided, of course, that the milk is not embalmed. ; )
Microwave popcorn still expanding nicely but in shrinking amounts
When I first ran a multifactor design of experiment (DOE) on microwave popcorn in 1993,* the bags contained 3.5 ounces of product. Since then, this product and many other foodstuffs suffered from shrinkflation—a way for their manufactures to fool us into paying the same for less. For example, Pop Secret—one of the snacks tested in my 1993 DOE, now comes in 3.2-ounce bags—a shrinkage of 8.6 percent over the years. Tricky!
I asked Google’s experimental Generative AI for stats on shrinkflation. GAI (my new go-to guy!) tells me that:
- The most common products to experience shrinkflation are savory snacks, chocolate, and sweets. (Popcorn fits the bill.)
- In the US, 71% of people have noticed shrinkflation, with 57% reporting multiple incidents in the past year. Baby boomers are more likely to notice shrinkflation than millennials and Gen Zers. (I am a baby boomer and I am well aware of this trend.)
- Shrinkflation can be harder to notice than price increases because the price of the item stays the same, making it harder to budget. (That’s the idea!)
- According to the US Bureau of Labor Statistics (BLS), shrinkflation has little impact on overall inflation rates. A BLS report from March said that the price of snacks inflated by 26% from January 2019 to October 2023. However, shrinkflation accounted for only 2.5 percentage points of the increase. (OK, so maybe we are making too big of a deal about this, but nobody likes to be tricked.)
The increasing cost of food products is currently creating a great deal of consternation, despite it seemingly abating. But so long as there’s plenty of delicious popcorn to share, even at a higher price for less of it, I don’t mind much.
However, when it comes to the recent trend for popcorn manufacturers selling “mini bags” with 1.5 ounces of product, I draw the line!
Hoping to cell-abrate meat substitutes before I die
Posted by mark in food science, Uncategorized on October 14, 2024
As a consultant on statistical design and analysis of experiments, I’ve been working with many leading-edge developers of cell-based meats (and fish). I am a carnivore—me loving a juicy burger, tender pulled pork, medium-rare steak or barbecued chicken. However, I’d happily switch to lab-grown protein once it passes a properly designed double-blind taste test. This will be a huge breakthrough by not killing animals and greatly reducing greenhouse gases—including “enteric fermentation” (nice way of referring to cow farts, ha ha).
Some experts do not foresee this happening in our lifetime according to this report last February by CBC. But after reading this cover story posted yesterday by Chemical & Engineering News on recent developments on lab-grown meats, I am more optimistic.
There is a fly in the food, so to speak, though: I cannot eat lab-grown meat while wintering in my Florida home—it’s been banned per this May 1 press release from Governor DeSantis. No fair!
“Today, Florida is fighting back against the global elite’s plan to force the world to eat meat grown in a petri dish or bugs to achieve their authoritarian goals.”
– Governor Ron DeSantis
By the way, I do agree with the Governor on one thing by not being a big fan of eating bugs. On the other hand, I applaud a Stat-Ease client from Bulgaria—Nasekomo (meaning ‘‘insect’’)—for developing a high-protein chicken feed made from soldier flies. I helped one of their researchers on her experimentation after first being assured that the EU approves the use of their product only for animals, not humans. She told me that chickens who eat the fly-based food tend to be less aggressive and healthier. Sounds good to me: Cock-a-doodle-do!
Analytics explain why the NFL stiffs running backs
My Minnesota Vikings are on a roll this year due to unexpectedly stellar play from their quarterback Sam Darnold. After being drafted very highly, Darnold turned out to be a dud. But suddenly he blossomed—no doubt helped greatly by our superstar wide receiver Justin Jefferson. This Sunday the Vikings play in London against the New York Jets and their future hall-of-fame QB Aaron Rodgers.
There’s no doubt that quarterbacks are the most important factors for success in the NFL, so it’s no surprise that there’s a positive correlation of 0.7 between annual passing yards and annual revenue according to Harvard economist Roland Fryer.* But it’s quite shocking that he finds a negative correlation of 0.01 for the value of running backs. I agree with Fryer that its delightful to “see analytics put to good use but sad to see football’s best position taking a back seat.”
Go Darnold, go Vikes!
P.S. As reported earlier this year by SI, The NFL Treats Elite Wide Receivers Very Differently From Top Running Backs. As a case in point, they highlight the huge contract just signed by Jefferson. “Show me the money”—the demand given by the wide receiver to his agent Jerry McGuire played by Tom Cruise—isn’t working for running backs, though they do make a lot more money than kickers or punters as seen in this ESPN ranking of pay by position.
*Comments on “The Economics of Running Backs,” Wall Street Journal, September 4.
Australia overcomes USA for Olympian heights: Seriously?
Now that Tom Cruise swooped in on the Stade de France outside of Paris and carried off the Olympic flag to Los Angeles, the final reckoning can be made on which country ‘won’ the 2024 Summer Games. I figured that by tying for tops in gold medals and winning the most silver and bronze, the USA was the clear winner.
However, to be fair, one must take population by country into account (within reason by excluding very small countries such as Grenada, who only need to win a few medals top the Olympic chart on a per capita basis). Earlier this year Robert Duncan and Andrew Parece proposed a population-adjusted probability-based index “U”.*
See how your country ranks in by this measure in this final ranking for the Paris Olympics. Aussies rule—gold medals to all! The Peoples Republic of China, who outnumber Australians by 53 to 1, fall to 89th on the list—second to last. Ouch! Kudos to France for coming in second (silver) and Great Britain third (bronze). The USA ranks fifth—not too bad.
Congratulations to all the Olympians and the organizers of this summer’s games for a very entertaining spectacle. Let’s not bogged down by the medal counts—all who participated get full credit for their all-out efforts.
*Per equation 9 in their Journal of Sports Analytics vol. 10, no. 1, pp. 87-104, 2024, research paper on Population-adjusted national rankings in the Olympics
The secret sauce in Guinness beer?
Posted by mark in design of experiments on August 9, 2024
I highly recommend Scientific American’s May 25 Opinion by Jack Murtagh explaining How the Guinness Brewery Invented the Most Important Statistical Method in Science. It nicely illustrates the t test—a landmark statistical method developed by William Sealy Gosset to assess a key ingredient in Guiness beer for ideal bitterness and preservation—soft resin content in hop flowers. Gosset calculated that a 1% difference in the amount of soft resins in the hops, the best and cheapest being purchased from Oregon,* increased their value to the brewery by almost 11%.
“Near the start of the 20th century, Guinness had been in operation for almost 150 years and towered over its competitors as the world’s largest brewery. Until then, quality control on its products had consisted of rough eyeballing and smell tests. But the demands of global expansion motivated Guinness leaders to revamp their approach to target consistency and industrial-grade rigor. The company hired a team of brainiacs and gave them latitude to pursue research questions in service of the perfect brew.”
– Jack Murtagh
Back in 2017 on National Beer Day, celebrated yearly on April 7 to commemorate the end of USA’s prohibition of its sale, I saluted Gosset and his very useful t-test of the significance of one treatment versus another, that is, a simple comparative experiment.**
“They began to accumulate data and, at once, they ran into difficulties because their measurements varied. The effects they were looking for were not usually clearcut or consistent, as they had expected, and they had no way of judging whether the differences they found were effects of treatment or accident. Two difficulties were confounded: the variation was high and the observations were few.”
– Joan Fisher Box,*** “Guinness, Gosset, Fisher, and Small Samples,” Statistical Science, Vol. 2, No. 1 (Feb., 1987), pp. 45-52
To see how the t-test works, check out this awesome graphical app developed Even Miller. Using Stat-Ease software, I cross-checked it against a case study (Example 3.3) from the second edition of Box, Hunter and Hunters’ textbook Statistics for Experimenters. It lays out a simple comparative experiment by a tomato gardener who randomly splits 11 plants for treatment either with her standard fertilizer (A) or a far more expensive one (B) that supposedly produces far better yields. Here are the yield results in pounds, which you can assess using the t test:
- 29.9, 11.4, 25.3, 16.5, 21.1
- 26.6, 23.7, 28.5, 14.2, 17.9, 24.3
On average the new fertilizer increases the yield by nearly 2 pounds, but is the difference statistically significant? That would be good to know! I have the answer, but it would be no fun to tell you, being so easy to find out for yourself.
PS: Due to the large variation between plants (a greater than 6-pound standard deviation!), this tomato study is badly underpowered. If you do an experiment like this, do anything possible to get more consistent results. Then assess power for whatever the difference is that makes changing fertilizers worthwhile. For example, let’s say that with better plant management you got the standard deviation reduced to 3 pounds and a difference of 4 pounds is needed at a minimum to make the switch in fertilizer cost-effective. Then, using Stat-Ease software’s power calculator, I figure you would need to test 3-dozen plants each in your randomized experiment to achieve an 80% probability of detecting a difference of 4 pounds given a 3-pound standard deviation. I hope you like tomatoes!
*As reported by Eat This Podcast in their 4/10/18 post on Guinness and the value of statistics
***I was very fortunate to meet Joan Fisher Box in 2019 as related in this StatsMadeEasy blog/
What not to wear to a dinner hosted by mosquitos
Posted by mark in Nature, Uncategorized on August 2, 2024
Yesterday I stopped by Minnesota’s Metropolitan Mosquito Control District (MMCD) booth at our local county fair. They display live mosquito larvae swimming in a shallow pan of water. Visitors can pipette them on to a slide and view them with a microscope. Fascinating!
Thanks to the mosquito control services by MMCD (and/or developments reducing habitat) I’ve seen a dramatic decrease in these pests since moving into my home in Stillwater almost 30 years ago. However, there were plenty of ‘skeeters at the Anderson family get-together up north at Pine Terrace Resort last month. While packing for our getaway, my wife advised that to be less attractive to these flying insects I bring white or lightly colored clothes and none with any reds. Being a professional skeptic of such assertions, I immediately looked for any science to support her advice. As usual, she was right, as you can see in this 2022 publication by Nature on The olfactory gating of visual preferences to human skin and visible spectra in mosquitoes.
If you are put off by too much information, watch this LIVENOW interview of co-author Jeffrey A. Riffell—a biology professor at the University of Washington, Seattle. I like his heads-up that mosquitos learn not to bite people swatting them away and go for easier prey. In other words, if you are going for a hike in the woods, bring along someone who would rather get bitten up than look like a city slicker. Then diligently swat all mosquitos over to your trail-mate—better to look like a fool than be bitten-upped cool.
PS: I am a big fan of DEET repellants for deterring mosquitos and, equally important, ticks. I also wear a cap treated with permethrin, which is a real game changer as advised by Hiking Thru Life. Of course, in areas where mosquitos gather in visible clouds, covering up completely, starting with a head net, is the only way to go. Given the huge increase in mosquito-borne and tick-borne diseases in the United States and elsewhere, it’s best to “fight the bite”.
Design of experiments (DOE): Secret weapon for model rocketry
Posted by mark in science, Uncategorized on June 27, 2024
Attracted by its focus on model rockets, I took a summer class on physics at Macalester College in my early teens. What a blast—literally! I really enjoyed learning about force, mass, acceleration and all the other aspects underlying aerospace. (Keep in mind this being the height of the 1960s race to the Moon.) But the best part was building a scale model of the Saturn V featuring multiple solid propellant motors and a parachute recovery system. For the grand finale of our class, we successfully launched our rocket. The parachute did deploy. However, our ship drifted over Saint Paul’s magnificent urban forest (soon to be decimated by Dutch elm disease) and got hopelessly hung up 100 feet overhead.
These great memories from my youth came back to me earlier this year when asked for advice on validating the OpenRocket simulator. The question came in from a mentor using Stat-Ease® 360 software on a low-cost educator license to support a high-school rocket club achieve the American Rocketry Challenge goals for altitude and flight duration. I happily deferred this request for stat help to my colleague Joe—a physics PhD who plays a dual role providing statistical advice and programming. Without getting into the details (after all, this is rocket science!), suffice it to say that, yes, our DOE software does provide “the right stuff.”
By the way, just last week a NASA sounding rocket carrying student experiments reached an altitude of 70 miles. See the video for the launch. (I advanced it to the countdown. After the blast off, move on. That is the only exciting bit.)
What I find most amazing is that the nose cone on this rocket can carry up to 80 plastic cubes as payload. These accommodate experiments by 11-18 year old students. Check out this Cubes in Space STEM program. Page down to the BREAKING NEWS about an important discovery made by a group of elementary students from Ottawa. I recommend you watch the CTV video—very impressive to hear from such science-savvy grade-schoolers. They will go far!