The Buck Stops Here

Cool Music

2012-05-24T12:31:00.000-05:00

I was emailing a friend recently about how many of my favorite bands are British or Irish: U2, Keane, Travis, Coldplay, Oasis, the Corrs, Muse, Radiohead, Sting, George Michael, Grammatics, Your Vegas, Animal Kingdom, Morning Parade, A Silent Film, Editors. (I like a lot of US bands too -- Deas Vail, Switchfoot, Death Cab, Eisley, Copeland, PFR, etc. -- but a disproportionate number are from over there.) His thoughtful response:

I don't know what it is, but British artists continually show a better sense of melody and structure than American ones. American artists seem to get pigeonholed easily: if they're pop it's either bubblegum or seductive; if they're rock it's either metal or confessional grunge-type stuff; and then there's hip hop, which I don't need to discuss. Indie is all over the map, and some of it is great. But indie can't be compared to what happens in Britain because it's not very commercially successful, and it's hard to trace any sort of development or tradition there. . . .

There's this broad middle ground in British music where artists can blend elements of the above and be both commercial and artistic at the same time. That's what American music needs. But I'm not sure if you get it just by giving artists more artistic freedom. There may be a genuine cultural difference in the ability to produce and appreciate good melody.

Anyway, here are some songs that I recently heard on Sirius/XM's Alt Nation, which is where I come across new music these days. Many are British, which is what gave rise to the above:

1. Noel Gallagher, "If I Had a Gun". When I first heard this, I was vaguely reminded of Oasis, which is no surprise.

2. A Silent Film, "Driven by Their Beating Hearts".

3. Morning Parade, "Headlights". This band is from Essex, and their first album came out in March. Musically reminds me of Coldplay a bit.

4. The Joy Formidable, "A Heavy Abacus". A Welsh band whose debut album came out last year.

5. Death Cab for Cutie, "Crooked Teeth".

6. Radiohead, "Lotus Flower".

7. Purity Ring, "Obedear". A little more electronic than the stuff I usually like, but reminded me of Andain.

8. Beach House, "Myth".

9. Editors, "Munich".

Why Does David Coleman Dislike Fiction?

2012-05-21T14:57:00.000-05:00

The answer is: he doesn't, and to say so is a gross misrepresentation.

As background, David Coleman is the former Rhodes Scholar who has been deeply involved in drafting the Common Core standards, and who was recently announced as the new head of the College Board. Diane Ravitch, erstwhile historian and current twitterer and blogger against all things associated with any education reformer, recently accused Coleman of promulgating Common Core standards that basically eliminate fiction from school curricula:

I have been told by several people who attended David Coleman’s lectures that he speaks disparagingly of fiction. That’s why the Common Core standards permit 50% fiction in the early grades but only 25% fiction in high school. I don’t get it.

First, because teachers should make that decision.

Second, because I can’t imagine a well-developed mind that has not read novels, poems and short stories. . . . [LEAVING OUT SEVERAL PARAGRAPHS ABOUT POETRY THAT RAVITCH LOVES AND THAT WOULD SUPPOSEDLY BE ELIMINATED BY COLEMAN]

Maybe David Coleman thinks that education is wasted on the young. But how sad it would be if future generations of young people never read the poems and stories and novels that teach them not only how to think but how to feel, how to dream, how to imagine worlds far beyond those they know.

To accuse Coleman, or the Common Core standards (little as I care to defend them), of eliminating all "poems and stories and novels" is simply wrong. The Common Core standards DO speak of having 50% of reading be non-fiction in early grades and 70% in high school, but those figures apply to the entire curriculum, not to English classes.

David Coleman himself made that clear in a comment on Ravitch's blog:

1) The 70/30 balance in grades 6-12 does not mean that students read mostly non-fiction in ELA classrooms. It applies to all student reading and explicitly includes the reading of content rich non-fiction in history, social studies, science and technical subjects. The majority of 6-12 ELA remains devoted to literature with some room for literary non-fiction.

2) The standards require the careful study of poems, novels, and drama in K-12. Such things as the study of Shakespeare is required, American literature and wonderful aspects of poetry. Let there please be no misunderstanding that literature in these standards does not remain a central part of student and teacher work.

But anyone who had looked at the Common Core standards would have known this already. To quote the Common Core website:

In K–5, the Standards follow NAEP’s lead in balancing the reading of literature with the reading of informational texts, including texts in history/social studies, science, and technical subjects. In accord with NAEP’s growing emphasis on informational texts in the higher grades, the Standards demand that a significant amount of reading of informational texts take place in and outside the ELA classroom. Fulfilling the Standards for 6–12 ELA requires much greater attention to a specific category of informational text—literary nonfiction—than has been traditional. Because the ELA classroom must focus on literature (stories, drama, and poetry) as well as literary nonfiction, a great deal of informational reading in grades 6–12 must take place in other classes if the NAEP assessment framework is to be matched instructionally.

Teachers of senior English classes, for example, are not required to devote 70 percent of reading to informational texts. Rather, 70 percent of student reading across the grade should be informational.

Maybe 70% shouldn't be set in stone, but if high school students read mostly novels, stories, and poetry in English class, and then read challenging non-fiction for their classes in history, science, the arts, etc., why wouldn't all that additional reading add up to about the 70/30 ratio that the Common Core standards suggest? In other words, Common Core gets to a 70/30 non-fiction-to-fiction ratio not by eliminating fiction but by adding more non-fiction. Is this a bad idea? Ravitch doesn't say, as she's too busy making the false claim that future students will "never read" fiction any more.

Moreover, look at one of the reasons Coleman offers for trying to emphasize non-fiction reading:

We in America in K-5 assessment and curriculum focus 80% of our time on stories, on literature. That is the dominant work that is done in the elementary school and that's what's tested on exams and that's what's in our textbooks. However, the research is overwhelmingly clear and actually Dr. Steiner has been an early proponent of this research at its earlier stages, that in kindergarten through 5th grade, the general knowledge that you develop in those years plays a crucial predictive role in not only your performance in those other disciplines, like science and history, but your ability to read more complex text itself. That is, the elementary school's a magnificent place for students to learn about the world through reading. Whoever thought otherwise?

So the core standards for the first time demand that 50% of the text students encounter in kindergarten through 5th grade is informational text, meaning primarily text about science and history, text about the arts, the text through which students learn about the world. That is a major shift and if you think about what's happening in this country unintentionally literature and stories dominated the elementary curriculum. And then we expanded the literacy block. So we made the literacy block 80% of the time.

Guess what that meant? We destroyed history and science in the elementary school. The core standards are a chance to regain the proper role of the elementary school teacher, to bring their students into the world, to spend equal time on informational and story, and in that way build a real foundation for literacy--that is the first major step. And the standards strongly encourage that the knowledge that's built through this reading and read alouds and then students reading themselves in history and science and the arts--it is coherent both within grades and across grades that students are building this foundation of knowledge.

Ravitch ought to love this. She claims all the time that schools spend too much time on reading and math to the exclusion of a rich curriculum in science, history, the arts, etc. She ought to be applauding Coleman and the Common Core standards for trying to require more challenging non-fiction reading across all subjects. Instead, she is demonizing Coleman by accusing him of disliking fiction.

Books I've Read in the Past Couple of Years

2012-05-03T21:47:00.002-05:00

Not even halfway to an exhaustive list, but these are highly recommended:

More Good Music

2012-04-28T21:41:00.000-05:00

Sucre, "When We Were Young." Sucre is a side project with Stacy DuPree-King of Eisley, her husband Darren King of MuteMath, and Jeremy Larson. Just lovely.

Wolf Gang, "The King and All Of His Men"

The Temper Trap, "Sweet Disposition"

Death Cab for Cutie, "Meet Me On the Equinox"

Taylor Swift and the Civil Wars, "Safe and Sound"

Brandon Flowers, "Crossfire"

A Useful Quote for Social Scientists

2012-04-16T17:31:00.001-05:00

A less profound application of the less-is-more principle is to our habits of reporting numerical results. There are computer programs that report by default four, five, or even more decimal places for all numerical results. Their authors might well be excused because, for all the programmer knows, they maybe used by atomic scientists.

But we social scientists should know better than to report our results to so many places. What, pray, does an r = .12345 mean? or, for an IQ distribution, a mean of 105.6345? For N = 100, the standard error of the r is about .1 and the standard error of the IQ mean about 1.5. Thus, the 345 part of r = .12345 is only 3% of its standard error, and the 345 part of the IQ mean of 105.6345 is only 2% of its standard error. These superfluous decimal places are no better than random numbers. Theyare actually worse than useless because the clutter they create, particularly in tables, serves to distract the eye and mind from the necessary comparisons among the meaningful leading digits. Less is indeed more here.

Jacob Cohen, Things I Have Learned (So Far), American Psychologist 45 no. 12 (1990): 1304-12.

New Music

2012-04-15T21:35:00.002-05:00

Keane's forthcoming album seems very promising, from the sound of the new video (below), which returns to the melodic piano-based pop sound of their first two albums. Tom's voice sounds stronger than ever.

Nick Pitera, whose day job is animation with Pixar, has an amazingly versatile voice, as shown by his performance of selections from Phantom of the Opera (and no, he's not lip-syncing the female voice):

Switchfoot, which I've liked since 2000's "Learning to Breathe, has a new album, and they're even playing here locally in a couple of weeks. May have to catch that one.

Other new stuff I've liked:

Animal Kingdom, "Strange Attractor":

The Shins, "Simple Song":

Young the Giant, "Apartment":

Pentatonix, "Somebody That I Used to Know" (remake of Gotye/Kimbra):

The China Study: Invalid from the Start

2012-03-29T18:36:00.000-05:00

I recently read one of the most famous books defending veganism: The China Study: The Most Comprehensive Study of Nutrition Ever Conducted And the Startling Implications for Diet, Weight Loss, And Long-term Health. The title of the book derives from a massive nutritional study carried out in China, the original of which I procured as well (Junshi et al., Diet, Life-style, and Mortality in China: A study of the characteristics of 65 Chinese counties, Oxford Univ. Press, 1990).

The "China Study" has been amply criticized elsewhere, but I wanted to highlight one criticism that, to my mind, is fatal.

Here's what Colin Campbell and his co-authors did when they studied China (for more details, see here and here). They started with county-by-county death rates from some 2,400 Chinese counties in 1973-75. They then went to China 10 years later in 1983 and 1984, whereupon they visited 65 selected counties out of 2,400.

In each county, they picked 100 people randomly and tested their blood ("Diet," p. 9). They gave three-day diet surveys to 30 families in each county (p. 16). At the end of all this, they came up with 367 different variables about mortality, urine and blood characteristics, diet, etc.

They originally published this research in the Junshi et al. book mentioned above. Roughly 800 of this book's 894 pages consist of listing each variable one by one, along with that variable's correlation with every other variable. One can hardly imagine anything more tedious and useless, except perhaps for this spoof:

FORTHCOMING WORKS BY DR. BOLI.

Dr. Boli’s Handy Table of Computations. Every number in the world added to, subtracted from, multiplied by, and divided by every other number, with complete operations shown, for the benefit of students of mathematics. The largest and most comprehensive work of its kind. Now available: Vol. 1, “1, Part 1.”

Tediousness is the least of the China Study's faults, however. We all know that correlation is not causation, but the China Study doesn't even rise to the level of producing meaningful correlations in the first place.

This is because of the ecological fallacy. This fallacy lies in attributing characteristics to an individual when all you know is information about a group that he belongs to. For example, Alabama is more likely to vote Republican than Massachusetts. Alabama also has more black people than Massachusetts. But it would be completely wrong to conclude that black people are Republicans. Within both Alabama and Massachusetts, black people are more likely to vote Democratic than white people. And that's what matters if you're trying to predict how individual people will vote.

So go back to the China Study. They purported to find, for example, that liver cancer was inversely related to blood cholesterol (see The China Study book, p. 78). It would be one thing if the China Study authors were claiming to have tested liver cancer patients and to have found high cholesterol levels. That wouldn't show anything about what causes liver cancer, of course: perhaps liver cancer causes high cholesterol, perhaps there's a third factor that causes both liver cancer and high cholesterol, or perhaps people who are prone to liver cancer are also prone to have high cholesterol for completely separate reasons.

But all of that is beside the point, because there isn't any genuine correlation between liver cancer and high cholesterol in the first place. The researchers didn't test the blood of anyone who died of liver cancer (or anything else, for that matter). The death rates all come from 1973-75, a full decade before the researchers went around testing different people's blood. All that the researchers really found was that if there's a Chinese county with a high liver cancer death rate in 1973-75, and if you go there 10 years later to test the blood of people who almost certainly don't have liver cancer and who are up to four decades younger than those who died in the 1970s, you might find high cholesterol levels.

This is about as valid as a study finding that because I can run a marathon, and because my grandmother died from breast cancer a little over 10 years ago, marathons are correlated with breast cancer. (The new bestselling book: "The Marathon Study: Why Running Endangers Your Health.").

It's a bit sad. For all of the effort and good intentions of the researchers, the China Study isn't even relevant. It certainly isn't a reason to advise people to do anything different about their diet.

A Lovely Bach Piece

2012-03-11T15:21:00.001-05:00

One of my favorite Bach pieces: Cantata No. 54, written for today (3rd Sunday of Lent). Here, it's played by Glenn Gould and chamber orchestra, with introductory comments by Gould himself:

Good Quote on Multitasking

2012-03-05T09:35:00.001-06:00

From Peter Bregman, 18 Minutes:

Our minds move considerably faster than the outside world. You can hear far more words a minute than someone else can speak. We have so much to do, why waste any time? While you're on the phone listening to someone, why not use that extra brainpower to book a trip to Florence?

What we neglect to realize is that we're already using that brainpower to pick up nuance, think about what we're hearing access our creativity, and stay connected to what's happening around us. What we neglect to realize is that it's not extra brainpower. It may be imperceptible, but it's all being used, right then and there, in the moment. And diverting it has negative consequences.

All of us can probably recognize the following experience: you're talking to someone on the phone, and you suddenly realize that he is checking his email or browsing a webpage or doing something else. How do you know? Because he stops responding normally (e.g., he says "yeah" or "right" at the wrong times or with too much delay). Whoever you're talking to probably thinks that he can multitask just fine, but you know otherwise, because the conversation suddenly feels like it's going nowhere.

If you can tell when someone else is multitasking during a conversation, it's probably a good idea not to try it yourself.

How Economic Specialization Led to the Welfare State

2012-02-28T13:26:00.001-06:00

A smart bit of analysis of economic history:

Something I haven't seen mentioned in any economics text I've read -- book, article, blog post, etc. -- is why the welfare state, in some form or other, always pops up when people begin to specialize.

It is not some far-off side effect of specialization that gave birth to the welfare state, but the very fact of specializing more and more narrowly in our job tasks.

How Much Does Testing Cost?

2012-02-27T10:59:00.005-06:00

From Douglas Harris' book "Value-Added Measures in Education," p. 203:

"Currently, less than 2 percent of current K-12 expenditures go to fund the entire state and federal systems of standards, assessments, and accountability, and switching from tests now in use to IB tests, for example, would increase costs from $15 to $34 per student to $113 to $161 per student."

A Trivia Quiz for Dogs

2012-02-26T18:04:00.000-06:00

Inspired by Dr. Boli (see here and here), here is a trivia quiz for your dog:

1. Who was the American author of The Morning After and Last Night in Paradise?
2. Who was the Danish pietist preacher who died in 1738?
3. Who was the French author of La vie et la passion de Dodin-Bouffant, gourmet (translation: The Passionate Epicure)?
4. Who was the President of Germany from 2010 to 2012?
5. Who has been described as “most eminent German philosopher between Leibniz and Kant”?
6. What is the common English name for the wading bird Philomachus pugnax?

ANSWERS AFTER THE BREAK:

Answers:

1. Roiphe.
2. Wulf.
3. Rouff.
4. Wulff.
5. Wolff.
6. Ruff.

Don't Believe the "Defenders" of Teachers: Teachers Do Matter

2012-01-28T17:49:00.001-06:00

You often see education commentators trying to suggest that bad school performance is almost entirely the fault of poverty and other external factors, not the fault of poor teaching. In making this claim, commentators often point to variance in student test scores that is allegedly "explained" by teachers. For example, Anthony Cody says, "Even Eric Hanushek, the economist who has done more to advance these evaluation systems than anyone, admits that teachers only account for around ten percent of the variability in student test scores."

Family and income are surely important, but the "10% of variance" argument is wrong for at least two reasons:

First, in statistical terms, saying that teachers account for 10% of the variance in student test scores does NOT mean that teachers are unimportant. Wrong, wrong, wrong. (At the end of the blog post, I say more about what explaining variance means.)

The eminent Harvard professors Rosenthal and Rubin explained this in a 1982 article, "A Simple, General Purpose Display of Magnitude of Experimental Effect," Journal of Educational Psychology 74 no. 2: 166-69 (that article isn't available online, but is described here).

As luck would have it, Rosenthal and Rubin address the precise example of a case wherein 10% of the variance was explained:

We found experienced behavioral researchers and experienced statisticians quite surprised when we showed them that the Pearson r of .32 associated with a coefficient of determination (r²) of only .10 was the correlational equivalent of increasing a success rate from 34% to 66% by means of an experimental treatment procedure; for example, these values could mean that a death rate under the control condition is 66% but is only 34% under the experimental condition. We believe . . . that there may be a widespread tendency to underestimate the importance of the effects of behavioral (and biomedical) interventions . . . simply because they are often associated with what are thought to be low values of r².

By analogy, saying that teacher quality explains 10% of the variance would be equivalent to saying that teachers can raise the passing rate from 34% to 66%. That's nothing to sneeze at, and it certainly isn't a reason for teachers to throw up their hands in dismay at the hopelessness of their task.

Second, the fact that teachers account for 10% of variance NOW, given a particular set of data points, tells us little or nothing about the true causal importance of teachers. As Richard Berk explains in his book Regression Analysis: A Constructive Critique, "Contributions to explained variance for different predictors do not represent the causal importance of a variable." 10% isn't a Platonic ceiling on what teachers can accomplish, and the proportion of variance explained tells us very little about how much impact teachers really do have.

A simple hypothetical example makes this clear: Imagine that all teachers in a school were of equal quality. Given equal teachers, any variation in student test scores would automatically have to arise from something other than differing quality of teaching. So a regression equation in that context might tell us that demographics explain a huge amount of the variation in test scores, while teaching quality explains nothing. But it would be completely wrong to conclude that demographics are inherently more important than teaching quality, or even that teaching quality doesn't matter. The exact opposite might be the case, for all that such a regression could tell us.

Moreover, if all teachers became twice as effective as they are now, there would still be variance among teachers and variance among student test scores, and teachers collectively might still "account" for a "small" amount of variance, but student performance might be much higher. The fact that teachers account for 10% of variance today (as large as that actually is) simply does not give us any sort of limit on how much student achievement could rise if the mean teacher effectiveness shifted sharply to the right.

So the would-be defenders of teachers can breathe a sigh of relief: value-added modeling might still be a shaky idea for several other reasons, but there's no need to denigrate the potential of teachers.

* * *

A more detailed statistical explanation:

The proportion of variance explained means is that if you take the Pearson product-moment correlation, and square it, you end up (after some algebra) with the following:

What does this mean? The denominator is calculated by taking all the individual Y's (in the education context, all of the student test scores that you're trying to explain), subtracting the average Y value, squaring all of the differences, and adding up all of the squared values. In the context of the following graph, the denominator gives us a measure of the total squared distance (in the vertical direction) that all of the red dots deviate from the average Y value.

The numerator tells us how far the regression line deviates from the average Y value. The regression line predicts that the Y values will be along the line itself, which obviously isn't exactly true. So the predicted Y values (that's what the little ^ sign over the Y means) have the average Y value subtracted, the difference is squared, and then all the squared differences are added up.

All in all, the "proportion of variance explained" figure is just a way to represent how close a regression line based on X will come to the actual red dots in the graph, compared to how close a line based on just the average red dot will come.

For the same reason that correlation is not causation, accounting for variance does not provide an upper limit for the true causal importance of a variable. As noted above, the level of variance "explained" is a bad way to determine how important X actually is. See D'Andrade and Hart, for example. UPDATE: See Cosma Shalizi's post on explaining variance.

Jeff Buckley's "Corpus Christi Carol"

2012-01-25T19:39:00.001-06:00

Just lovely:

Also this:

The New Groupthink

2012-01-17T15:05:00.000-06:00

From a New York Times article titled "The New Groupthink":

Our schools have also been transformed by the New Groupthink. Today, elementary school classrooms are commonly arranged in pods of desks, the better to foster group learning. Even subjects like math and creative writing are often taught as committee projects. In one fourth-grade classroom I visited in New York City, students engaged in group work were forbidden to ask a question unless every member of the group had the very same question.

I'm not sure why group seating in classrooms seems to have caught on so strongly. As a parent, I know that children are better behaved (if only by necessity) when they're not sitting close enough to bother someone else, mark on the other child's paper, etc.

A Case Study in Bias

2012-01-07T18:18:00.002-06:00

Two studies came out comparing the performance of schools or teachers. In the first case, Raj Chetty, John Friedman, and Jonah Rockoff came up with just about the most extensive and sophisticated study of teachers' value-added that I've ever seen. As highlighted in the New York Times, the study includes estimates for how much high-quality teachers improve their students' income years later, and also (see pp. 29 ff.) includes a new way to check for bias by looking at how cohorts of students change performance when a high or low value-added teacher arrives from somewhere else. Very cool.

But such a study, implying that some teachers are better than others, and that teacher quality can be revealed by how well their students do on tests (conditioning on prior achievement and student demographics), is disturbing to some people. Diane Ravitch tweeted at least 67 times the day the study came out, trying to undermine the study by questioning its lack of peer review (so far), the way in which it was conducted, and the very project of looking at test scores in the first place.

In the second case, there's a group called Educate Now in Louisiana that released a PDF chart (available here) that merely lists the schools in New Orleans identified by whether they are Recovery School District schools or voucher-accepting private schools, and then listing what percentage of students score above basic on English and Math in grades 3-5. That's all. No attempt to control for the individual students' prior achievement, no attempt to control for any student demographic variables such as poverty, no attempt to control for the fact that students are eligible for vouchers only if they had been attending a failing public school, no statistical analysis whatsoever.

This is as primitive as it gets, and is a horrible way to judge the merit of voucher schools (as I explained here).

Did Diane Ravitch tweet 67 times criticizing this purported attempt to compare voucher schools to public schools? No: right in the midst of her incessant criticism of an immeasurably superior study, she sent out one tweet that said, "How did voucher schools in New Orleans do?" followed by a link.

Ravitch here displays the worst sort of intellectual bias: when what looks like one of the best studies out there doesn't fit her ideology, she acts as if it is far more questionable than the baloney that she otherwise is happy to plug. To be sure, it's OK to ask questions about the new value-added study, what it means, how it was done, and whether it was oversold in the media. But it's not OK to pass along a worthless analysis of the merits of vouchers.

Anti-reformers need to think a bit more carefully about whether they want someone as their standard-bearer who doesn't know the difference between good and bad research (or, worse, who doesn't care).

"Starch Consumption Raises Risk Of Breast Cancer Coming Back"

2011-12-18T14:49:00.000-06:00

So read the headline on a news story recently. A new study found as follows:

Breast cancer survivors whose starch intake is above average have a greater risk of cancer recurrence compared to other breast cancer survivors, researchers from the University of California, San Diego explained at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, Dec. 6-10, 2011. The researchers added that it is in particular starch that raises the risk, and not just overall carbohydrates.

Plausible. But it turned out that all the researchers did was interview the women once a year about their diet, and women whose breast cancer came back were eating 2.3 GRAMS of carbohydrates more than the average per day, only half of which was starch. As far as I can tell, that's about as much as is in 1 tablespoon of cooked rice. So the headline was based on women claiming to have eaten an additional 1 tablespoon of cooked rice (or some equivalent) per day.

This does not strike me as a useful finding. There is no way that a once-a-year interview can pinpoint women’s carbohydrate consumption down to the tablespoon, and such a miniscule amount of starch surely can't be making a clinical difference anyway.

Charter Schools and Segregation

2011-11-24T17:49:00.006-06:00

Charter schools are often accused of "segregation" merely for serving too many black kids. One recent example of this criticism comes from Zoe Burkholder of Montclair State University in New Jersey, who has an article in Teachers College Record lamenting the fact that DC Prep Charter School is 98% black.

She does concede that black parents have a good reason to choose DC Prep: "parents in D.C. can choose between a traditional public school racked with violence and high dropout rates, or a charter school that is safe and promises to teach at least two of the '3 Rs.'" She even admits that "maybe anyone would prefer a charter school like DC Prep under these conditions."

But she immediately backs away from agreeing that black parents ought to have the option of choosing such a school:

But that doesn’t make it okay, and here is why. When you step back from DC Prep, and successful charter schools like it, what you see is a public school that is racially and socio-economically segregated and inherently very different from the form and function of the majority of public schools in America. . . . Since Horace Mann first rode horseback through New England to sell the idea of tax-supported “common schools” for all children, Americans have dared to dream that public education will instill in our citizenry the many capacities necessary for self-government: critical thinking, civic engagement, tolerance for diversity, an appreciation for the arts and sciences, a knowledge of global affairs, a critical understanding of American history, and the capacity for civil debate.

I've said this about Diane Ravitch before: If you're going to oppose the so-called "segregation" of charter schools, even though it arises from the completely voluntary choices of black parents, you should think twice before waxing so eloquent about Horace Mann's day, when it was often illegal for black people to attend school anywhere. Nor is it historically correct that "Americans" wanted "tolerance of diversity" in public schools during the 100+ years of officially-mandated segregation.

In any event, Burkholder makes the same mistake that the highly publicized Civil Rights Project (headed by Gary Orfield) made: she compares DC Prep Charter School to "the majority of public schools in America."

That comparison is completely meaningless. We know that charter schools are much more likely to be located in inner-city neighborhoods where the demographics are much different from the national average. Indeed, if an inner-city DC or Atlanta charter school had demographics that resembled the broader United States, that school would instantly be accused of promoting segregation by gathering too many white students in one place.

What Burkholder should have done is compare DC Prep to nearby traditional public schools. On that ground, it turns out that a 98% black charter school in a heavily black area of northeastern D.C. isn't that unusual. The closest traditional public school to DC Prep is Noyes Elementary, which is 96% black, 3% Hispanic, and all of zero percent white.

Yes, racial imbalance still exists. But attacking charter schools does nothing to get rid of it.

Momentum in Sports

2011-11-20T14:32:00.002-06:00

The Freakonomics blog makes a point that I think is wrong:

The best place to start is with a famous (for academia) paper from several years ago, called “The Hot Hand in Basketball: On the Misperception of Random Sequences.” As you can glean from that snazzy subtitle, the authors come down against momentum, arguing that a “hot streak” is really just a random sequence that we misperceive to be more meaningful than it is.

Ever try flipping a coin 100 times? You’ll be surprised at how many long, unbroken sequences of heads or tails you get. It’s easy to mistake that for a pattern, suggesting some kind of meaning or momentum, but it’s really just a pure illustration of randomness itself. The fact is that if you get 10 heads in a row, the next flip is no more likely to be heads (or tails, for that matter).

And so it is, for the most part, with hot hands and hot streaks and hot quarterbacks. In our Momentum video, you’ll hear Toby Moscowitz, the academic co-author of Scorecasting, discuss how pretty much everyone in football believes in momentum. But, having looked at a lot of NFL data, Moscowitz reaches a sobering conclusion: “There is a much stronger belief in momentum than is warranted by what we see in the data.”
* * *

Consider one example in our video, the Buffalo Bills’ redonkulous 32-point comeback against the Houston Oilers in 1993. As Chris “Mad Dog” Russo puts it: “You’re gonna tell me momentum had nothing to do with that game?!”

Okay, Chris, I’ll take a shot at telling you exactly that. You know why we’re still talking about that game? Because it was a massive anomaly – the kind of comeback that almost never happens. It was so rare that our brains have an easy time recalling it. (We do this with all anomalies – dramatic plane crashes, mass murders, and so on.) And when we recall something so easily, we tend to believe it’s far more common that it actually is.

The truth is that you’re bound to get a wild 32-point-comeback once in a while, just as you’re bound to get a streak of 10 or 12 heads too.

Here's the thing: a 32-point comeback might indeed be so rare that it fits within a statistically normal distribution as several standard deviations above the mean. This does NOT mean, however, that a 32-point comeback was itself a matter of random chance -- the 32-point comeback happened because of how a bunch of human beings performed on a given day, and their performance was not random at all. Their performance was affected non-randomly by their preparation and skills, their coaching, their choices of plays, and their confidence level (the latter of which would be dramatically affected if either team started to think that the "momentum" was heading in a particular direction).

Try an analogy: A 7-foot-tall man is a rarity, and if human height falls into a normal distribution, someone might make the following claim, akin to the dismissal of sports momentum: "This 7-foot-tall man's height might seem to have sprung from some genetic factor, but in fact, you find 7-foot-tall men in nature only as often as would be expected by chance. Therefore his height is just a matter of random chance, not genetics."

Well, the fact that this particular guy got the genes to be 7 feet tall might be random chance from the point of view of a statistician looking at all of humanity, but that in no way proves that his height was unrelated to genes. Similarly, the fact that one particular sports team had a huge amount of momentum on a particular day might be described as random chance, but that doesn't disprove the claim that it did have momentum then.

Songs I Like

2011-11-09T09:57:00.011-06:00

UPDATE: Here's a Spotify list of most of the songs below.

Deas Vail, “Desire.”

The National, “Exile, Vilify.”

Eisley, "One Day I Slowly Floated Away."

Eisley, "Memories."

Deas Vail, "Shoreline."

Jeff Buckley, "Corpus Christi Carol."

Copeland, “Should You Return.”

With Lions, “Our Great Rise.”

The Future of Forestry, “If You Find Her.”

Jonsi, “Tornado.”

Gotye with Kimbra, “Somebody That I Used to Know.”

The Honey Trees, “To Be With You.”

Eric Whitacre, “Lux Arumque.”

Espen Lind, “Scared of Heights.”

Kimbra, “Settle Down.”

The Reign of Kindo, “The Moments In Between.”

Peter Groenwald, “Wreckage.”
<p>&amp;lt;a href="http://petergroenwald.bandcamp.com/track/wreckage"&amp;gt;Wreckage by Peter Groenwald&amp;lt;/a&amp;gt;</p>

Yael Naim, “New Soul.”

Bat for Lashes, “Sleep Alone.”

Civil Twilight, “Human.”

Digital Daggers, “Surrender.”

Shiny Toy Guns, "You Are the One."

Dubstar, "Stars."

Muse, Undisclosed Desires.

Erin McCarley, "Pitter-Pat."

Deadmau5 and Kaskade, “I Remember.”

Marc Martel, "Somebody to Love."

Dredg, "Information."

Eden's Edge, "Blue Moon of Kentucky."

Lo-Pro, "Reach."

George Michael, "I Can't Make You Love Me."

And just for fun: George Michael, “1, 2, 3.”

What Causes Student Achievement?

2011-11-04T12:36:00.003-05:00

Dana Goldstein addresses that question:

As you can see, by estimating teacher effects at 20 percent, I've interpreted the research consensus quite generously. Matthew DiCarlo, a sociologist with the Shanker Institute, has looked at this same body of research and concluded that another 20 percent of the causes of student achievement gaps are "unobservable" (ex; differences in innate intelligence, statistical error, other mystery causes); and that the rest, about 60 percent, can likely be explained by all the myriad factors associated with socioeconomic status.

The parsing out of what causes student achievement seems very dubious. What if part of the way that socioeconomic status leads to higher achievement is that parents use it to buy houses in school zones with . . . better teachers? Seems very likely, but there's no way to tell with the usual models.

One way we could figure out how to divvy up responsibility would be to get 500 rich kids and randomly assign half to attend a school with teachers identified as horrible (but otherwise keeping everything else about the school the same, such as peers or school spending), and then compare them to the other rich kids who got to attend their regular school. Then you'd really be able to see how much rich kids were benefiting from being able to buy access to good teachers.

But you'd never be able to do such a study -- no one would sign up.

Memory and the Law

2011-10-19T14:29:00.001-05:00

All of the studies on the fallibility of memory should make us question the weight given to eyewitness testimony.

Good collection of essays

2011-10-16T08:15:00.003-05:00

From 52 prominent economists:

This is a compendium of fifty-four papers written by distinguished economists in response to an invitation by the National Science Foundation's Directorate for the Social, Behavioral and Economic Sciences (NSF/SBE) to economists and relevant research communities in August 2010 to write white papers that describe grand challenge questions in their sciences that transcend near-term funding cycles and are "likely to drive next generation research in the social, behavioral, and economic sciences." These papers offer a number of exciting and at times provocative ideas about future research agendas in economics. The papers could also generate compelling ideas for infrastructure projects, new methodologies and important research topics.

Contributors include James Heckman, Daron Acemoglu,
David Cutler, Esther Duflo, and Hal Varian.

Addicted to Running

2011-10-11T16:48:00.001-05:00

Someone who qualifies: "Woman Completes Chicago Marathon and Delivers Baby."

Interesting article on Steve Jobs

2011-10-10T17:47:00.001-05:00

Here.