There is a difficulty with giving The Bell Curve a chance

Friday, May 12th, 2017

Charles Murray explains his controversial book The Bell Curve:

In April, I recorded an interview of almost two and a half hours with Sam Harris for his Waking Up podcast, which, I learned only after I had done it, regularly attracts a few million listeners. We spent more than half of the interview discussing what is actually in “The Bell Curve” as opposed to what people think is in it. Both of us expected our Twitter feeds to light up with nasty reactions after the interview was posted. But the opposite happened. The nasty reactions were far outnumbered by people who said they had always assumed that “The Bell Curve” was the hateful pseudoscientific mess that the critics had claimed, but had now decided they wanted to give the book a chance. It has been a heartening experience.

However, there is a difficulty with giving “The Bell Curve” a chance. The paperback edition has 26 pages of front material, 552 pages of main text, a 23-page response to the critics, 111 pages of appendixes, another 111 pages of endnotes, and a 58-page bibliography. It’s a lot to get through. But there’s a shorter way to get a good idea of what’s in the book: Dick Herrnstein and I began each chapter with a summary that was usually about a page long. With the publisher’s permission, I have stitched all of those summaries together, along with selections from the Introduction and the openings to each of the four parts of the book. If these tidbits arouse enough interest that you buy the book, I will be delighted. But at this point in my life, my main objective is that a labor of love, written with a friend who I still miss twenty-three years after his death, be seen for what it is.

There just are not enough good schools to go around

Monday, May 8th, 2017

This recent New York Times piece on “the broken promises of choice” in New York City schools is so willfully naive it’s painful:

Within the system, there is a hierarchy of schools, each with different admissions requirements — a one-day high-stakes test, auditions, open houses. And getting into the best schools, where almost all students graduate and are ready to attend college, often requires top scores on the state’s annual math and English tests and a high grade point average.

Those admitted to these most successful schools remain disproportionately middle class and white or Asian, according to an in-depth analysis of acceptance data and graduation rates conducted for The New York Times by Measure of America, an arm of the Social Science Research Council. At the same time, low-income black or Hispanic children like the ones at Pelham Gardens are routinely shunted into schools with graduation rates 20 or more percentage points lower.

While top middle schools in a handful of districts groom children for competitive high schools that send graduates to the Ivy League, most middle schools, especially in the Bronx, funnel children to high schools that do not prepare them for college.

The roots of these divisions are tangled and complex. Students in competitive middle schools and gifted programs carry advantages into the application season, with better academic preparation and stronger test scores. Living in certain areas still comes with access to sought-after schools. And children across the city compete directly against one another regardless of their circumstances, without controls for factors like socioeconomic status.

Ultimately, there just are not enough good schools to go around. And so it is a system in which some children win and others lose because of factors beyond their control — like where they live and how much money their families have.

We send the kids with good grades and test scores to the selective schools and the kids with bad grades and test scores to the unselective schools, and that’s clearly unfair, because those unselective schools underperform the selective schools!

There just are not enough good schools to go around.

School has become an abnormal setting for children

Sunday, April 30th, 2017

School has become an abnormal setting for children,” according to Boston College psych professor Peter Gray, but “instead of admitting that, we say the children are abnormal.”

Arnold Kling adds this:

Those of us who grew up many decades ago probably would not want to trade our childhood for today’s childhood. My memories are of spending all day playing “hit the bat” out in the street, or practicing handstands in the yard, or playing board games. With no adult supervision.

Gray’s recent book on the topic is Free to Learn: Why Unleashing the Instinct to Play Will Make Our Children Happier, More Self-Reliant, and Better Students for Life.

He’s on to something, but I don’t completely agree him.

Tough, detail-oriented, and able to push themselves

Thursday, April 27th, 2017

Jennifer Bricker was born without legs and immediately given up for adoption by her Romanian-American parents:

But with the support of her adoptive family, Jen, in spite of her physical challenges, grew to become a champion athlete herself. By age 12 she was excelling in power tumbling — an acrobatic sport that combines artistic gymnastics and trampoline. She failed to understand why people singled out her achievements over those of her teammates. In 1998, she placed fourth in the all-around event at the Junior Olympics, the first physically challenged tumbler to finish so high. Her gymnastics idol growing up? Dominique Moceanu.

Her gymnastics idol, Dominique Moceanu, was one of the “Magnificent Seven” at the 1996 Summer Olympics in Atlanta — and turned out to be her older sister.

Nancy L. Segal describes her work on identical twins and non-twin siblings:

I have studied separated twins for many years, first from 1982 to 1991 as an investigator with the Minnesota Study of Twins Reared Apart (MISTRA). Today, I follow the progress of 16 young Chinese reared-apart twin pairs, as well as older twins separated due to unusual life events. I have seen striking examples of identical, reared-apart twins whose athletic talents coincided prior to any contact between them. Japanese-born twins Steve and Tom, raised by different families in the United States, both became competitive lifters and owners of bodybuilding gyms; Steve competed in the 1980 Olympics. Adriana and Tamara, born in Mexico and raised in New York, attended different Long Island colleges and found each other only after one was mistaken for the other. But both were already accomplished dancers and later performed together. Mark and Jerry, each six-foot-four, were both already volunteer firefighters when they met in their early thirties, each having developed the strength, stamina, and motivation to pursue the demanding role.

Studying twins, particularly separated-at-birth pairs, and separately reared non-twin siblings, is the best way to disentangle the genetic and environmental influences on individual similarities and differences. For example, such research could help determine if nature or nurture is the stronger factor in sports participation and achievement. But other physical actions and routines appear to have a genetic basis as well. Most reared-apart identical twins in the MISTRA group, for example, positioned their bodies the same way while standing for unposed photographs, which occurred less often among fraternal reared-apart pairs.

[...]

A 2005 twin study by Dutch researcher Janine Stubbe showed that genetic effects on sports participation increase after adolescence, as children gain the freedom to enter and create environments compatible with their genetic proclivities. Her subsequent 2006 study confirmed this finding, and numerous twin studies from around the world have found similar genetic effects on oxygen uptake, anaerobic capacity and power, cardiac mass, and other performance-related fitness characteristics.

Claude Bouchard of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, is one of the few researchers to combine twins and adoptees in genetic studies of sports-related traits. His 1984 study of submaximal physical working capacity — an index of aerobic metabolism and oxygen transport that boosts muscular activity and endurance — found the greatest resemblance between identical twins, followed by fraternal twins, biological siblings, and adoptive siblings and showed strong genetic influence on these traits. These findings have serious implications for how we make the most of our physical abilities and overcome our limitations.

[...]

Dominique and Jen are both extroverted, driven, and competitive. They are also perfectionists and “performance hams” who love being in front of a crowd. Their voices sound the same, whether speaking or laughing, and they use their hands a lot in conversation. Jen recognizes traits in Dominique that she sees in herself, such as leadership and initiative. Both are tough, detail-oriented, and able to push themselves emotionally and physically, perhaps explaining their commitment to the long hours and personal sacrifices required for success in gymnastics.

According to Dominique, though, an important difference between them is that Jen has “super-high confidence, whereas we were beaten down by our father. I walked on eggshells.” Jen herself credits her competitive success and self-esteem to the support of her adoptive family and community — and now to the DNA she shares with her sisters as well.

[...]

My reared-apart twin research reveals that close relationships can develop quickly between such pairs. In 2003, I found that over 70 percent of reunited identical twins and nearly 50 percent of reunited fraternal twins recalled feeling closer than or as close as best friends upon first meeting. These figures jumped to about 80 percent and 65 percent, respectively, for the closeness they reported feeling when surveyed. Yet only about 20 percent of the twins felt the same way toward unrelated siblings they had always known. In 2011, I reported my findings that most parents of young separated twins observed an immediate rapport between the children when reunited. These findings suggest that perceptions of similarity (mostly behavioral) are the social glue that draws and keeps reunited twins and siblings together, underlining the universal importance of family.

They weren’t cogitating, recollecting, differentiating

Tuesday, April 25th, 2017

Radiologists were asked to evaluate X-rays while inside an MRI machine that could track their brain activity:

(There’s a marvellous series of recursions here: to diagnose diagnosis, the imagers had to be imaged.) X-rays were flashed before them. Some contained a single pathological lesion that might be commonly encountered — perhaps a palm-shaped shadow of a pneumonia, or the dull, opaque wall of fluid that had accumulated behind the lining of the lung. Embedded in a second group of diagnostic images were line drawings of animals; within a third group, the outlines of letters of the alphabet. The radiologists were shown the three types of images in random order, and then asked to call out the name of the lesion, the animal, or the letter as quickly as possible while the MRI machine traced the activity of their brains. It took the radiologists an average of 1.33 seconds to come up with a diagnosis. In all three cases, the same areas of the brain lit up: a wide delta of neurons near the left ear, and a moth-shaped band above the posterior base of the skull.

“Our results support the hypothesis that a process similar to naming things in everyday life occurs when a physician promptly recognizes a characteristic and previously known lesion,” the researchers concluded. Identifying a lesion was a process similar to naming the animal. When you recognize a rhinoceros, you’re not considering and eliminating alternative candidates. Nor are you mentally fusing a unicorn, an armadillo, and a small elephant. You recognize a rhinoceros in its totality — as a pattern. The same was true for radiologists. They weren’t cogitating, recollecting, differentiating; they were seeing a commonplace object. For my preceptor, similarly, those wet rales were as recognizable as a familiar jingle.

In 1945, the British philosopher Gilbert Ryle gave an influential lecture about two kinds of knowledge. A child knows that a bicycle has two wheels, that its tires are filled with air, and that you ride the contraption by pushing its pedals forward in circles. Ryle termed this kind of knowledge — the factual, propositional kind — “knowing that.” But to learn to ride a bicycle involves another realm of learning. A child learns how to ride by falling off, by balancing herself on two wheels, by going over potholes. Ryle termed this kind of knowledge — implicit, experiential, skill-based — “knowing how.”

The two kinds of knowledge would seem to be interdependent: you might use factual knowledge to deepen your experiential knowledge, and vice versa. But Ryle warned against the temptation to think that “knowing how” could be reduced to “knowing that” — a playbook of rules couldn’t teach a child to ride a bike. Our rules, he asserted, make sense only because we know how to use them: “Rules, like birds, must live before they can be stuffed.” One afternoon, I watched my seven-year-old daughter negotiate a small hill on her bike. The first time she tried, she stalled at the steepest part of the slope and fell off. The next time, I saw her lean forward, imperceptibly at first, and then more visibly, and adjust her weight back on the seat as the slope decreased. But I hadn’t taught her rules to ride a bike up that hill. When her daughter learns to negotiate the same hill, I imagine, she won’t teach her the rules, either. We pass on a few precepts about the universe but leave the brain to figure out the rest.

Some time after Lignelli-Dipple’s session with the radiology trainees, I spoke to Steffen Haider, the young man who had picked up the early stroke on the CT scan. How had he found that culprit lesion? Was it “knowing that” or “knowing how”? He began by telling me about learned rules. He knew that strokes are often one-sided; that they result in the subtle “graying” of tissue; that the tissue often swells slightly, causing a loss of anatomical borders. “There are spots in the brain where the blood supply is particularly vulnerable,” he said. To identify the lesion, he’d have to search for these signs on one side which were not present on the other.

I reminded him that there were plenty of asymmetries in the image that he had ignored. This CT scan, like most, had other gray squiggles on the left that weren’t on the right — artifacts of movement, or chance, or underlying changes in the woman’s brain that preceded the stroke. How had he narrowed his focus to that one area? He paused as the thought pedalled forward and gathered speed in his mind. “I don’t know — it was partly subconscious,” he said, finally.

“That’s what happens — a clicking together — as you grow and learn as a radiologist,” Lignelli-Dipple told me. The question was whether a machine could “grow and learn” in the same manner.

Spoiler alert: yes.

How many jobs really require college?

Monday, April 24th, 2017

The conventional wisdom is that we need to send even more people to college, but Devin Helton is skeptical enough that he went through a master spreadsheet of employment in the United States and made his own assessment of what percent of jobs truly require college.

Here is a table with my results, compared to what the actual attendance rates are:

schooling-required-table

There is no plausible way that 60% of jobs will innately require a degree in ten years. If 60% of jobs require a college degree on paper, that requirement will be entirely artificial (due to credentialing laws and competitive signaling spiral/degree inflation — see for example DC’s new regulation that childcare workers must have college degrees).

The most surprising thing I noticed was how many jobs require almost no specialized study or training. Even in contrarian, anti-college intellectual circles, it is popular to say we need more vocational education and apprenticeships. But skilled trades are only around 15% of jobs. The majority of jobs require no special training. They are jobs like cashier, driver, orderly, real estate agent, customer service agent, store clerk, house painter, or laborer.

Less than 15% of jobs can be plausibly said to need more study than the classic high school education.

If we want to make the working class better off, we should subsidize wages, not unnecessary education:

Consider the goods and services that make up a good and comfortable life: high-tech gizmos, gas heating, indoor plumbing, a well-built home, access to a skilled doctor, good restaurants, good beer, parks, well-built infrastructure, a stroll down a street with pretty buildings, etc. If you look at the production process for those goods and services, only a small percent of the workers involved need a college degree. And most degrees granted do not improve the production process — how does granting millions of degrees in “business”, “communications” or “social science” lead to more and better of these products? It doesn’t. And in fact, by channeling so many people into the college pipeline, we have lost out on the skills that did make for the good life. We have lost the artisans that once created beautiful streetscapes and ornate architectural detailing. We have less money to spend on infrastructure. We have more debt, and more stress.

Furthermore, even in the engineering fields, much of the know-how exists exclusively inside the productive organization — not inside the textbooks. Every engineer, when getting a job, has a big adjustment period as they learn how things are actually done. They learn why the schoolbook version was simplified or out-dated, and they learn the real techniques and tricks and tooling that they actually need to know to make things work.

In the past few decades, America has become more educated in terms of degrees. But in reality, people like my dad were training Chinese engineers to replace them, as the boomers retired and the high-tech job moved overseas. And now Forbes tells us that the Kindle cannot be made in America, because the essential technological production no longer exists here. According to policy wonks — who measure skills and education by number of years people spend sitting in chair — we have become more educated. But if you look at the actual knowledge needed to build high-tech goods, the issue is a lot more murky.

His recommendations:

  • Separate schooling from credentialing.
  • Create a set of free, online high school and college degree programs that any American could enroll in, and pursue at their own pace.
  • At age 13, give everyone a $100k education voucher.
  • Legalize and normalize apprenticeship contracts.

The lowest layer of the pyramid is the foundation

Thursday, April 13th, 2017

It’s hard to find a teacher who doesn’t make reference to Bloom’s Taxonomy, Doug Lemov notes, because it’s part of the language of teaching, but there’s a problem:

Bloom’s Taxonomy is often represented as a pyramid with the understanding — intended or accidental — that teachers should try to get to the top. That’s the nature of pyramids, I guess.

Bloom's Taxonomy Pyramid

Generally when teachers talk about “Bloom’s taxonomy,” they talk with disdain about “lower level” questions. They believe, perhaps because of the pyramid image which puts knowledge at the bottom, that knowledge-based questions, especially via recall and retrieval practice, are the least productive thing they could be doing in class. No one wants to be the rube at the bottom of the pyramid.

But this, interestingly is not what Bloom’s argued — at least according to Vanderbilt’s description. Saying knowledge questions are low value and that knowledge is the necessary precondition for deep thinking are very different things. More importantly believing that knowledge questions — even mere recall of facts — are low value doesn’t jibe with the overwhelming consensus of cognitive science, summarized here by Daniel Willingham, who writes,

Data from the last thirty years lead to a conclusion that is not scientifically challengeable: thinking well requires knowing facts, and that’s true not simply because you need something to think about. The very processes that teachers care about most — critical thinking processes such as reasoning and problem solving — are intimately intertwined with factual knowledge that is in long-term memory (not just found in the environment)

In other words there are two parts to the equation. You not only have to teach a lot of facts to allow students to think deeply but you have to reinforce knowledge enough to install it in long-term memory or you can’t do any of the activities at the top of the pyramid.

If Andre Agassi’s dad could do everything all over again

Saturday, April 1st, 2017

I don’t follow tennis, so I didn’t realize that Andre Agassi’s dad was a former Olympic boxer from Iran:

“When people didn’t have my nuanced take on him they just represented him as abusive. But my dad was clear. He said: ‘Andre, I know how I’ve lived and I know who I am and who I’m not. If I could do everything all over again I would change only one thing – I wouldn’t let you play tennis.’ I’d pulled the car over when he said: ‘I would only change one thing.’ I said, ‘Wow, why’s that Dad?’ He said: ‘Because I’d make you play baseball or golf so you can do it longer and make more money.’ I got back on the freeway with a chuckle.”

A Tale of Two Bell Curves

Monday, March 27th, 2017

Bo and Ben Winegard tell a tale of two Bell Curves:

To paraphrase Mark Twain, an infamous book is one that people castigate but do not read. Perhaps no modern work better fits this description than The Bell Curve by political scientist Charles Murray and the late psychologist Richard J. Herrnstein. Published in 1994, the book is a sprawling (872 pages) but surprisingly entertaining analysis of the increasing importance of cognitive ability in the United States.

[...]

There are two versions of The Bell Curve. The first is a disgusting and bigoted fraud. The second is a judicious but provocative look at intelligence and its increasing importance in the United States. The first is a fiction. And the second is the real Bell Curve. Because many, if not most, of the pundits who assailed The Bell Curve have not bothered to read it, the fictitious Bell Curve has thrived and continues to inspire furious denunciations. We have suggested that almost all of the proposals of The Bell Curve are plausible. Of course, it is possible that some are incorrect. But we will only know which ones if people responsibly engage the real Bell Curve instead of castigating a caricature.

How to Gain New Skills

Friday, March 24th, 2017

In his How to Gain New Skills guide for students, Ulrich Boser (Learn Better) discusses an experiment that took place years ago at a Catholic all-girls school in New York City:

As part of the experiment, the girls were taught how to play darts for the first time, and the two psychologists conducting the study divided the young women into some groups. Let’s call members of the first group “Team Performance,” and they were told that they should learn the game of darts by trying to throw the darts as close to the center of the board as possible. In other words, the researchers informed the women that the best way to win was to rack up some points.

The psychologists also pulled together another group of young women. Let’s call them “Team Learning Method,” and they learned to play darts very differently. The researchers had these girls focus on the process of gaining expertise, and the women started by focusing on how exactly to throw the darts, mastering some basic processes like “keep your arm close to your body.” Then, after the women showed some proficiency, they were encouraged to aim at the bull’s eye, slowly shifting from some process goals to some outcome goals like hitting the target.

Finally, there was the control group. Their instructions? The researchers told them to learn to “do their best.” In other words, these young women could take any approach that they wanted to learning darts. Let’s think of this group as “Team Conventional Wisdom.”

To learn more about the experiment, I met up with Anastasia Kitsantas, who ran the study together with psychologist Barry Zimmerman. While the experiment took place some years ago, Kitsantas still has the darts stashed away in her office at George Mason University, and on a rainy afternoon, she pulled out the little yellow missiles from an office cabinet to show them to me, laying the darts out like an important relic from some forgotten South American tribe.

Kitsantas held onto the darts because of the study’s surprisingly large outcomes, and by the end of the experiment, the young women on Team Learning Method dramatically outperformed the others, with scores nearly twice as high as Team Conventional Wisdom. The women also enjoyed the experience much more. “Several of the students asked me to teach them more about darts after the experiment. They kept asking me for weeks,” Kitsantas told me.

The best basketball player in the world is not the tallest

Thursday, March 23rd, 2017

Even a strong predictor of outcome is seldom able to pick out the very top performer, Stephen Hsu notes — e.g., taller people are on average better at basketball, but the best player in the world is not the tallest:

This seems like a trivial point (as are most things, when explained clearly), however, it still eludes the vast majority. For example, in the Atlantic article I linked to in the earlier post Creative Minds, the neuroscientist professor who studies creative genius misunderstands the implications of the Terman study. She repeats the common claim that Terman’s study fails to support the importance of high cognitive ability to “genius”-level achievement: none of the Termites won a Nobel prize, whereas Shockley and Alvarez, who narrowly missed the (verbally loaded) Stanford-Binet cut for the study, each won for work in experimental physics. But luck, drive, creativity, and other factors, all at least somewhat independent of intelligence, influence success in science. Combine this with the fact that there are exponentially more people a bit below the Terman cut than above it, and Terman’s results do little more than confirm that cognitive ability is positively but not perfectly correlated with creative output.

Strong Predictor Graph

In the SMPY study probability of having published a literary work or earned a patent was increasing with ability even within the top 1%. The “IQ over 120 doesn’t matter” meme falls apart if one measures individual likelihood of success, as opposed to the total number of individuals at, e.g., IQ 120 vs IQ 145, who have achieved some milestone. The base population of the former is 100 times that of the latter!

Cloaks, Daggers, and Dice

Thursday, March 16th, 2017

South by Southwest included a talk called Cloaks, Daggers, and Dice, which examined how the CIA uses games:

In “Collection,” Clopper’s first CIA game, teams of analysts work together to solve international crises against a ticking clock. His second title, “Collection Deck,” is a Pokémon-like card game in which where each card represents either an intelligence collection strategy or a hurdle like red tape or bureaucracy.

[...]

Also speaking on the panel was Volko Ruhnke, who is an intelligence educator at the CIA and a freelance game designer. Ruhnke said he is particularly interested in one type of game: a simulation tabletop game to train analysts and help with analytic tasks. It could help forecast complex situations by forcing players to handle multiple scenarios simultaneously.
Ruhnke himself created a commercial board game to simulate the Afghanistan conflict and walk players through military, political, and economic issues in the region. It gives players “a much more dynamic understanding of the issues of modern Afghanistan,” Ruhnke said, adding that a similar game could be of use internally at the CIA as well.

Volko Ruhnke is famous — in the wargaming community — for designing the card-driven wargames Labyrinth: The War on Terror, 2001–? and Wilderness War. He was also the original designer of GMT Games’ COIN series, which includes Cuba Libre, A Distant Plain, and Liberty or Death: American Insurrection.

Homeowners’ Quest for the Best Schools

Tuesday, March 14th, 2017

Parents will move to a new neighborhood and pay a huge premium to live near a good school:

For some home buyers, there is no factor more important than the public schools their children will attend. They analyze student-body performance on standardized tests, school rankings, what percentage of alumni go on to four-year colleges and which schools send students to Ivy League or top-tier state universities. They then uproot their lives to move within these districts’ boundaries, where homes can cost hundreds of thousands of dollars more than nearby homes zoned to different schools.

In La Cañada Flintridge, Calif., a city in Los Angeles county, the acclaimed La Cañada Unified School District determines the real-estate market, agents say. “I’m very busy in March, when the private-school rejection letters go out,” said Anne Sanborn, a real-estate agent with Sotheby’s International Realty in Pasadena. When parents find out their kids haven’t been accepted at elite private schools, they start house hunting in La Cañada, Ms. Sanborn said.

Ms. Sanborn added that “there is a mass exodus from La Cañada when their kids graduate high school,” as families sell their homes and seek neighborhoods closer to downtown Los Angeles or Pasadena.

Parents don’t seem to care which way the causality runs:

Online tools that measure student performance have made it easier for home buyers and agents to assess schools across the country.

For example, GreatSchools, an Oakland, Calif., nonprofit, rates schools based primarily on how well students perform on statewide assessments and has provided rankings to real-estate websites Zillow, Trulia, Move and Realtor, said Weezie Hough, director of strategic partnerships.

In an analysis of 1.6 million home listings in the U.S. through the first six months of 2016, Realtor.com found that houses in public-school districts with GreatSchools ratings of 9 or 10, the highest scores possible, were priced, on average, 77% higher than homes in nearby districts with scores of 6 or lower. Additionally, homes located in top districts sell four days faster — at 58 days — than the national median of 62 days, the analysis found.

Dismal Voucher Results Surprise Researchers

Sunday, March 12th, 2017

Three new studies show surprisingly bad results from school vouchers:

The first results came in late 2015. Researchers examined an Indiana voucher program that had quickly grown to serve tens of thousands of students under Mike Pence, then the state’s governor. “In mathematics,” they found, “voucher students who transfer to private schools experienced significant losses in achievement.” They also saw no improvement in reading.

The next results came a few months later, in February, when researchers published a major study of Louisiana’s voucher program. Students in the program were predominantly black and from low-income families, and they came from public schools that had received poor ratings from the state department of education, based on test scores. For private schools receiving more applicants than they could enroll, the law required that they admit students via lottery, which allowed the researchers to compare lottery winners with those who stayed in public school.

They found large negative results in both reading and math. Public elementary school students who started at the 50th percentile in math and then used a voucher to transfer to a private school dropped to the 26th percentile in a single year. Results were somewhat better in the second year, but were still well below the starting point.

This is very unusual. When people try to improve education, sometimes they succeed and sometimes they fail. The successes usually register as modest improvements, while the failures generally have no effect at all. It’s rare to see efforts to improve test scores having the opposite result. Martin West, a professor at the Harvard Graduate School of Education, calls the negative effects in Louisiana “as large as any I’ve seen in the literature” — not just compared with other voucher studies, but in the history of American education research.

There’s always the chance that a single study, no matter how well designed, is an outlier. Studies of older voucher programs in Milwaukee and elsewhere have generally produced mixed results, sometimes finding modest improvements in test scores, but only for some subjects and student groups. Until about a year ago, however, few if any studies had shown vouchers causing test scores to decline drastically.

In June, a third voucher study was released by the Thomas B. Fordham Institute, a conservative think tank and proponent of school choice. The study, which was financed by the pro-voucher Walton Family Foundation, focused on a large voucher program in Ohio. “Students who use vouchers to attend private schools have fared worse academically compared to their closely matched peers attending public schools,” the researchers found. Once again, results were worse in math.

If the voucher programs are new, and all the existing private schools are aimed at (slightly) better-than-average students, perhaps the schools are just a terrible fit.

Can critical thinking actually be taught?

Monday, February 27th, 2017

Can critical thinking actually be taught?

Decades of cognitive research point to a disappointing answer: not really. People who have sought to teach critical thinking have assumed that it is a skill, like riding a bicycle, and that, like other skills, once you learn it, you can apply it in any situation. Research from cognitive science shows that thinking is not that sort of skill. The processes of thinking are intertwined with the content of thought (that is, domain knowledge). Thus, if you remind a student to “look at an issue from multiple perspectives” often enough, he will learn that he ought to do so, but if he doesn’t know much about an issue, he can’t think about it from multiple perspectives. You can teach students maxims about how they ought to think, but without background knowledge and practice, they probably will not be able to implement the advice they memorize. Just as it makes no sense to try to teach factual content without giving students opportunities to practice using it, it also makes no sense to try to teach critical thinking devoid of factual content.