Thursday, July 27, 2006

"No Child Left Behind" is beyond uninformative. It is deceptive

CHARLES MURRAY points out below that Blacks and Hispanics are still lagging about as much as they ever did. So the burdens imposed by NCLB are not getting compensatory results. Murray knows WHY the gap is not closing but he does not pursue that below

Test scores are the last refuge of the No Child Left Behind Act (NCLB). They have to be, because so little else about the act is attractive. NCLB takes a giant step toward nationalizing elementary and secondary education, a disaster for federalism. It pushes classrooms toward relentless drilling, not something that inspires able people to become teachers or makes children eager to learn. It holds good students hostage to the performance of the least talented, at a time when the economic future of the country depends more than ever on the performance of the most talented. The one aspect of the act that could have inspired enthusiasm from me, promoting school choice, has fallen far short of its hopes. The only way to justify NCLB is through compelling evidence that test scores are improving. So let's talk about test scores.

The case that NCLB has failed to raise test scores had been made most comprehensively in a report from the Civil Rights Project at Harvard University, released just a few weeks ago. The Civil Rights Project has an openly liberal political agenda, but the author of the report, Jaekyung Lee, lays out the data in graphs that anyone can follow, subjects them to appropriate statistical analyses, and arrives at conclusions that can stand on their scholarly merits: NCLB has not had a significant impact on overall test scores and has not narrowed the racial and socioeconomic achievement gap.

Is it too early to tell? As a parent who has had children in public schools since NCLB began, I don't think so. The Frederick County, Md., schools our children have attended have turned themselves inside out to try to produce the right test results, with dismaying effects on the content of classroom instruction and devastating effects on teacher morale. We actually lost our best English teacher to the effects of high-stakes testing. "I want to teach my students how to write," he said, "not teach them how to pass a test that says they can write." He quit.

So, yes, I think that if we parents have had to put up with these kinds of troubling effects on our children's schooling for four years, we are entitled to expect evidence of results. After all, "accountability" is NCLB's favorite word, and the Department of Education is holding school systems accountable for improvements in test scores with a vengeance. Sauce for the goose, sauce for the gander.

The Department of Education will undoubtedly produce numbers to dispute the findings of the Civil Rights Project, which brings me to the point of this essay. Those numbers will consist largely of pass percentages, not mean scores. A particular score is deemed to separate "proficient" from "not proficient." Reach that score, and you've passed the test. If 60% of one group--blondes, let's say--pass while only 50% of redheads pass, then the blonde-redhead gap is 10 percentage points.

A pass percentage is a bad standard for educational progress. Conceptually, "proficiency" has no objective meaning that lends itself to a cutoff. Administratively, the NCLB penalties for failure to make adequate progress give the states powerful incentives to make progress as easy to show as possible. A pass percentage throws away valuable information, telling you whether someone got over a bar, but not how high the bar was set or by how much the bar was cleared. Most importantly: If you are trying to measure progress in closing group differences, a comparison of changes in pass percentages is inherently misleading.

Take the case of Texas, from which George Bush acquired his faith in NCLB. As the president described it to the Urban League in 2003: "In my state, Texas, 73% of the white students passed the math test in 1994, while only 38% of African-American students passed it. So we made that the point of reference. We had people focused on the results for the first time--not process, but results. And because teachers rose to the challenge, because the problem became clear, that gap has now closed to 10 points." President Bush's numbers are accurately stated. They are also meaningless.

Any test that meets ordinary standards produces an approximation of what statisticians call a "normal distribution" of scores--a bell curve--because achievement in any open-ended skill such as reading comprehension or mathematics really is more or less normally distributed. The tests that produce anything except a bell curve are usually ones so simple that large proportions of students get every item correct. They hide the underlying normal distribution, but don't change it. Thus point No. 1, that using easy tests and discussing results in terms of pass percentages obscures a reality that NCLB seems bent on denying: All the children cannot be above average. They cannot all even be proficient, if "proficient" is defined legitimately. Some children do not have the necessary skills. Point No. 2 goes to the inherent distortions introduced by the use of pass percentages: Because of the underlying normal distribution, a gain in a given number of points has varying effects on group differences depending on where the gain falls.

To illustrate point No. 2, consider a test that has a hundred-point scale with a mean of 50 and a standard deviation of 15 (the standard deviation, a measure of the variability of the scores, tells you how tall and skinny or how short and broad the bell curve will be). How many students are involved when a range of, say, 10 points is at issue? The shaded areas in Figure 1 show two possibilities.

The total area under the bell curve includes all the students. The shaded area on the left includes all those with a score of 40 to 49 points--24.8% of all students, if the distribution is perfectly normal. The shaded area on the right includes all those with a score of 80 to 89 points--just 1.9% of all students. Suppose we are still comparing redheads and blondes. If the mean score of redheads goes from 40 to 50, it has risen all the way from the 25th to the 50th percentile of all students. If the blonde mean goes from 80 to 90, it has moved merely from the 98th to the 99th percentile of all students. You do not have to be a statistician to see that these built-in features of normally distributed scores--gains that are equal in points are not equal in the number of students they affect or in the percentile distances that students move--complicate the use of pass percentages when comparing groups.

If you want to get deeper into the math, you may visit a quirky and provocative Web site,, run by someone who calls himself La Griffe du Lion. I surmise that he is an established scholar--a quantitative discipline seems likely--who once published on the fraught topic of group differences, learned how unpleasant and even professionally perilous that can be, and decided to remain anonymous henceforth. In any case, his technical skills are first rate. Click on the topic line entitled "Closing the Racial Learning Gap" for a much more detailed version of the argument and data that I am presenting here.

For our purposes, you need know only this: If the real difference between two groups, measured as it should be with means and standard deviations, remains constant, the size of the pass-percentage gap between two groups changes nonlinearly in a mathematically inevitable way. In other words, if there really is a constant, meaningful difference between groups, you can generate a curve that predicts how the point gap will change as tests are made easier or harder or as students become more or less competent. La Griffe has done this, and his curve fits the Texas data almost perfectly. In Figure 2, the white pass rate is used as the basis for predicting the size of the white-black gap. The circles represent the observed sizes of the test score gap from 1994 to 2002.

Test scores in Texas went up for both blacks and whites. Maybe that's good news, representing real gains in learning for everyone, or maybe it's not so good, representing the effects of teaching to the test. The data Texas reports do not permit a judgment. But the black gains are almost exactly what would be predicted if the magnitude of the underlying black-white difference remained unchanged. If there really was closure of the gap, all that Texas has to do is release the group means, as well as information about the black and white distributions of scores, and it will easy to measure it. Whatever the real closure may be, however, it cannot come close to the dramatic reduction that President Bush found in the difference between black and white pass rates.

In this instance, the percentage-passed measure misleadingly showed a huge reduction in the black-white achievement gap. But look at the left-hand side of the curve. In a state that imposes tough standards--for example, one that establishes a threshold that only 40% of whites pass--across-the-board improvements in scores can misleadingly show an increase in the white-black achievement gap when none occurred.

Question: Doesn't this mean that the same set of scores could be made to show a rising or falling group difference just by changing the definition of a passing score? Answer: Yes. At stake is not some arcane statistical nuance. The federal government is doling out rewards and penalties to school systems across the country based on changes in pass percentages. It is an uninformative measure for many reasons, but when it comes to measuring one of the central outcomes sought by No Child Left Behind, the closure of the achievement gap that separates poor students from rich, Latino from white, and black from white, the measure is beyond uninformative. It is deceptive.



The Education Secretary praised independent schools yesterday for helping children to become more rounded individuals by teaching sport, music and drama and allowing them to develop the social skills needed in the workplace. Alan Johnson, the MP for Hull West and Hessle, is widely tipped as Labour's next deputy leader. He made the comments a day after revealing that he had appealed to a private school to admit the gifted son of a constituent because there were no suitable state schools in the area. His speech to the National Family and Parenting Institute in London irritated teachers' unions and leftwingers.

He told parents: "One of the reasons why independent schools get such good results, apart from the level of selection and the extra resources, is the time they spend with children doing sport, music and drama, building social skills, confidence and team-working. "This helps children develop not just academic and vocational skills but social skills as well. These skills are vital in today's workforce where the ability to communicate, interact and engage are essential - they are the skills which employers increasingly look for first."

Mr Johnson said that schools could play a role in the community and help children to develop not just academic and vocational skills, but also social skills. The former postman and grammar school boy said that some primary schools were trying to develop good team-working and communication skills in young children through the "seal" programme, which is on trial in Nottingham.

In February, the managers of 222 top businesses said that they did not expect to receive applications from graduates "with the correct skills". The reason, they said, was that students spent too much time studying and not enough time joining clubs, where they might learn how to work in teams and give presentations. Poor spelling, grammar and arithmetic were also problems.

John McDonnell, the Labour MP for Hayes and Harlington and a fierce opponent of private schools, dismissed Mr Johnson's comments. He said: "It runs counter to all the evidence . . . that comprehensive education builds up social cohesion, whereas private education reinforces the divisions."

Teachers' leaders said that the minister had shown naivety. Steve Sinnott, general secretary of the National Union of Teachers, said that one of the biggest selling points of private schools was smaller class sizes, which made it easier for teachers to give pupils more individual attention. "Reducing class sizes has a direct impact on the time teachers can spend with children," he said. The only limit on class sizes for state schools was 30 for children aged 5 to 7. Mick Brookes, general secretary of the National Association of Head Teachers, said: "We think there are a lot of independent schools which provide an excellent education and we would really love state schools to have the resources to do the same."

Mr Johnson's speech was edited before being posted on his department's website. The edited version omitted any reference to independent schools.When asked why, an adviser said: "This should be as delivered - but some of the party political sections have been removed for propriety reasons."



For greatest efficiency, lowest cost and maximum choice, ALL schools should be privately owned and run -- with government-paid vouchers for the poor and minimal regulation.

The NEA and similar unions worldwide believe that children should be thoroughly indoctrinated with Green/Left, feminist/homosexual ideology but the "3 R's" are something that kids should just be allowed to "discover"

Comments? Email me here. For times when is playing up, there is a mirror of this site (viewable even in China!) here. My home page is here


No comments: