Wednesday, September 29, 2010

Merit Pay Fails Another Test. By Diane Ravitch

One of the signature issues of businesspeople and conservative Republicans for the past 30 years has been merit pay. They believe in competition, and they believe that financial rewards can be used to incentivize better performance, so it seems natural for them to conclude that merit pay or performance pay would incentivize teachers to produce better results.

Note that they assume that most people—in this case, teachers—are lazy and need a promise of dollars to be incentivized to get higher scores for their students. It never seems to occur to them that many people are doing their best (think people who play sports, always striving to do their best without any expectation of payment) and continue to do so because of intrinsic rewards or because of an innate desire to serve others. Teachers should certainly be well compensated, but not many enter the classroom with money as their primary motivation.

Although teachers need and want higher pay, they are strongly opposed to individual merit pay. They know that it destroys the collaboration and teamwork that are essential to the culture of the school. They know this even though few of them are familiar with the work of W. Edwards Deming, the business guru, who warned American business against ratings and merit pay. (See Andrea Gabor's The Man Who Discovered Quality, Chapter 9.) Deming said it nourishes rivalry and short-term planning, while undermining morale and long-term planning.

Few people realize that merit pay schemes have been tried again and again since the 1920s. Belief in them waxes and wanes, but the results have never been robust.

Now we have the findings of the most thorough trial of teacher merit pay, conducted by first-rate economists at the National Center for Performance Incentives. Many people expected that this trial would show positive results because the bonus for getting higher scores was so large: Teachers in the treatment group could get up to $15,000 for higher scores.

After a three-year trial, the researchers concluded that the teachers in the treatment group did not get better results than those in the control group, who were not in line to get a bonus. There was a gain for 5th graders in the treatment group, but it washed out in 6th grade.

Bottom line: Merit pay made no difference. Teachers were working as hard as they knew how, whether for a bonus or not.

But to what effect? The very next day after the release of the Nashville study, the U.S. Department of Education handed out many millions of dollars for merit-pay programs across the country and announced its intention to spend $1.2 billion on merit pay.

Ideology trumps evidence. The enduring puzzle is why the Obama administration clings so fiercely to the GOP philosophy of incentives and sanctions as the levers for change, despite lack of evidence for their efficacy.

Friday, September 24, 2010

Turning schools into robot factories. By Joanne Yatvin

I never miss reading the newspaper comics. Not for entertainment, but because I think their creators are some of the most intelligent and well-informed people on the public scene. As a group, they have mastered the subtleties of language, politics, philosophy, and human behavior.

Right about now I am struck by how many comics are dealing with the beginning of the school year and how uniform their messages are: Children aren’t happy about going back to school.
This is not good-natured humor. It reflects pretty accurately the feelings I hear expressed by my grandchildren and the other children I meet.

Although the excitement of new clothes and school supplies seems to soften the blow, the thought of being confined all day to over-crowded classrooms and hard seats and allowed to speak only after raising one’s hand is not a pretty prospect. Unfortunately, this picture gets uglier every year as demands for more and harder work increase, and the old respites of recess, art, music, and physical education disappear. By law, adults get breaks during their workday, but not children.

As a teacher educator and educational researcher, I have been visiting classrooms for years, and, for the most part, I don’t like what I see. Many of the once excellent teachers I know have been reduced to automatons reciting scripted lessons, focusing on mechanical skills, and rehearsing students for standardized tests. The school curriculum has become something teachers "deliver" like a pizza and students "swallow" whole, whether or not they like mushrooms.

Kindergartens that used to be places for children to learn social behavior, songs, dances, and poetry; how to build cities with blocks, play store, and express feelings with crayons and paint, are now cheerless cells for memorizing letter sounds and numbers. In one kindergarten I visited last year, children recited all the words in their little books without ever recognizing that they were part of a story.

In a first-grade classroom, I watched children march in circles at mid-morning, waving their arms because there was no longer a recess to refresh their bodies and spirits. Still, there was time enough for them to shout out the sounds of letters in chorus everyday and to memorize the words "onomatopoeia" and "metaphor."

In the upper elementary grades I saw both English and math taught by formulas. Students were given a list of the parts of a standard essay, told to use them in order and to begin with a question or a surprising statement. They were also taught the formula for dividing by fractions (as if anyone ever does such a thing) and the Pythagorean theorem (useful whenever you want to know the length of the hypotenuse of a right triangle).

Many school districts have also adopted summer homework policies, usually requiring students to read a prescribed list of books. This past summer my grandnephew, who is entering 9th grade, had to write a legal brief defending or condemning Martin Luther, although he had not been taught anything about that writing form or that famous man in 8th grade.

With the new Common Core Standards, created by experts who will never be tested on them, school life will grow even more onerous.

Algebra has been moved down to the 8th grade, and geometry, always a tenth grade elective, is now required of all ninth graders. Wordsworth’s "Preface to the Lyrical Ballads," which I read as a graduate student, is on the 9th grade recommended reading list. Although, the knowledge, skills, and books in the standards are, on the whole, academically valid, they are scheduled to be taught to students two to four years too young to understand or appreciate them.

All this has happened because the politicians who now control America’s schools have adopted the worst aspects of European and Asian education, which were designed to maintain social class boundaries in those societies.

Out of a misguided belief that students’ test scores represent a country’s economic health and, perhaps, out of wounded pride; our leaders appear determined to convert our once great public schools into robot factories and to extinguish the brilliance and imagination that have fueled our country’s greatness for more than 200 years.

Wednesday, September 22, 2010

Published Online: September 21, 2010 Merit Pay Found to Have Little Effect on Achievement By Stephen Sawchuk

The most rigorous study of performance-based teacher compensation ever conducted in the United States shows that a nationally watched bonus-pay system had no overall impact on student achievement—results released today that are certain to set off a firestorm of debate.

Nearly 300 middle school mathematics teachers in Nashville, Tenn., voluntarily took part in the Project on Incentives in Teaching, a three-year randomized experiment conducted by researchers affiliated with the National Center on Performance Incentives at Vanderbilt University. It was designed to study the hypothesis that a large monetary incentive would cause teachers to seek ways to be more effective and boost student scores as a result.

But it yielded only two small positive findings, limited to 5th graders in the second and third year of the experiment. No effects were seen for students in grades 6-8 in any year of study.

At the same time, however, participating teachers did not report finding the pay program’s goals for students out of reach or its impact on school culture damaging, two concerns that have been among those voiced by opponents of performance pay.

The implementation of the pay program “did not set off significant negative reactions of the kind that have attended the introduction of merit pay elsewhere,” the study’s authors write. “But neither did it yield consistent and lasting gains in test scores. It simply did not do much of anything.”

The findings arrive in a highly charged teacher-quality policy environment, in which many states and districts, with support from the Obama administration, are overhauling current practices for preparing, evaluating, and compensating teachers.

And they come at a particularly inopportune time for the U.S. Department of Education, which is scheduled to announce a fresh slate of grantees this month under a federal program designed to seed merit-pay programs for teachers and principals.
Union Cooperation

The study, known as POINT for the Project on Incentives in Teaching, was designed by the researchers, with the input of the 76,000-student school district and the support of the local teachers’ union affiliate and the Tennessee Education Association. Matthew G. Springer, the director of the Nashville-based center, cited the unions’ cooperation as a crucial factor in the study’s successful implementation.

The executive director of the Tennessee Education Association said the reputation of the researchers played an important role in the union’s decision to sign on. “We thought it was a chance to work with researchers whose processes and reputation we trust, and they were coming at this question with no particular ideology,” said Al Mance. “We said, ‘OK, this is something we really want to know. We won’t have a better opportunity than this.’ ”

The program was instituted in Nashville between 2006-07 and 2008-09 and covered 296 middle school math teachers in grades 5-8.

Participating teachers, all volunteers, were assigned to either a treatment group eligible to receive significant pay bonuses or a control group earning normal wages. Those in the treatment group were rewarded with bonuses between $5,000 and $15,000 based on whether their students’ achievement rose by a specified amount over the course of a year. The gains were calculated using a value-added methodology designed to filter out other aspects that could have influenced the scores.

The teachers were also randomized in clusters, so that there was at least one treatment and one control teacher in every middle school. And the program contained no quotas, so all teachers whose students performed at the specified targets earned the additional pay.

Over the course of the study, attrition reduced the number of participating teachers to only 148, and researchers carefully tracked that pattern over time to make sure it did not change the equivalence of the two groups in such a way as to skew the results. Only one teacher withdrew from the study; most of the attrition occurred because teachers were reassigned or left the district.

On average, students taught by the teachers taking part in the program did not make larger academic gains than those taught by teachers in the normal wage group.The sole exception was in grade 5 in the second and third years of study.

In those years, the incentive pay was linked to statistically significant increases in student scores—an increase, the report states, equal to between a third and a half year of learning. But the effect did not appear to persist.

“By the end of 6th grade,” the study states, “it does not matter whether a student had a treatment teacher in grade 5.”

The researchers performed a number of tests to try to make sense of the grade 5 findings, including to see whether there was evidence of a reallocation of time from other subjects to math, or cheating on the exams. But none of them turned up any firm explanation.

“It really is puzzling,” said Mr. Springer. “It just raises questions about what’s different about 5th grade and what factors played a role. Was it student development? The curriculum? Teaching or classroom structures?”
A Sparse Field

In interviews, scholars who study performance-based pay and teacher incentives and who were familiar with the POINT findings but not involved in the experiment, widely praised its rigorous design.

“It’s a really well-designed study, and it’s really important because a lot of the debate about performance pay has been evidence-free,” said Steven N. Glazerman, a principal researcher at Mathematica Policy Research, a Princeton, N.J.-based evaluation firm.

The existing empirical research literature on incentive pay has been limited in scope, size, and relevance. Much of the experimental research concerns programs in other countries.

What’s more, many of the existing performance-pay programs studied in the United States award far smaller bonuses, and scholars have questioned whether those amounts were enough to affect a change in teacher behavior. ("Merit-Pay Model Pushed by Duncan Shows No Achievement Edge," June 9, 2010.)

But the POINT findings, said some researchers and advocates, appear to put to rest the idea that incentive pay in and of itself is enough to spur better teacher performance.

“A lot of the discussion about performance pay is based on a faulty assumption that the reason we don’t have higher test scores is that teachers are shirking their responsibilities,” said Helen F. Ladd, a professor of public policy and economics at Duke University in Durham, N.C., about the findings.

Ms. Ladd added, however, that she was “a little surprised” that the findings were not more mixed. She anticipated that teachers might work even harder over the short term to win bonuses. But that supposition was not borne out by the study.

Mr. Mance of the Tennessee Education Association said the study confirms what many teachers and unions have long believed: that teachers are already hardworking. For this study to show positive results, he said, “you’d have to have teachers who were saving their best strategies for an opportunity to get paid for them, and that is an absurd proposition.”

Researchers cautioned, however, that the Nashville experiment does not provide answers to many other questions about incentive pay. For instance, it wasn’t designed to test the hypotheses that pay incentives might serve as a draw to a different population of teacher-candidates or as an incentive for other candidates to stay in the profession—thus potentially changing the quality of the teacher workforce.

“I personally believe that the biggest role of incentives has to do with selection of who enters and who stays in teaching—how incentives change the teaching corps through entrance and exits,” said Eric A. Hanushek, a professor of economics at the Hoover Institution at Stanford University. “The study has nothing to say about this.”

And because the study looks at an incentive program strictly as pay, it remains unclear how far the findings can be extrapolated to incentives with more features, such as professional development, differentiated roles, or a new teacher-evaluation system.Many well-known incentive-pay models, including Denver’s ProComp system and the popular Teacher Advancement Program, sponsored by the Santa Monica, Calif.-based National Institute for Excellence in Teaching, contain such elements. ("Denver Voters Approve Tax Hike to Underwrite Incentive-Based Teacher Pay ," Nov. 11, 2005, and "TAP: More Than Performance Pay," April 1, 2009.)

One finding suggests that the debate over the use of test scores as a measure of student learning and teacher effectiveness remains a top concern for teachers. Surveys of participants for POINT found that a majority generally supported higher pay for teachers whose students made achievement gains. Yet in 2009, about 85 percent said they felt the test-based criteria for determining effectiveness were too narrow.

That lack of buy-in, the study’s authors postulated, might have contributed to the finding of no differences in how the control and treatment groups affected instruction.
Inopportune Moment

From a policy perspective, performance pay has experienced a type of renaissance over the past six years, following the introduction in 2004 of the ProComp and in 2006 of the federal Teacher Incentive Fund, or TIF, a program established under the administration of President George W. Bush to seed performance-pay systems.

Since 2008, the Obama administration has embraced TIF and has put its own stamp on performance pay through the Race to the Top competition, which encouraged states to institute new systems for evaluating teachers and for using the results of those evaluations to inform pay decisions.

“While this is a good study, it only looked at the narrow question of whether more pay motivates teachers to try harder,” a spokeswoman for the U.S. Department of Education said in an e-mail. “What we are trying to do is change the culture of teaching by giving all educators the feedback they need to get better while rewarding and incentivizing the best to teach in high need schools and hard-to-staff subjects.”

The effects of the report on that policy agenda are not clear, but in the short run at least, proponents of merit pay are likely to steer clear of replicating the features of the Nashville program.

“Anyone about to implement a performance-based pay system will want to pay very close attention to this study, to learn from the POINT program’s successes, but especially its shortcomings,” said Mr. Glazerman of Mathematica. “These groups bear a heavy burden to figure out how their own programs can demonstrate a greater impact than what we’ve seen so far.”

“I think most people today agree that the existing compensation structure for teachers is broken, but we don’t know what a better way is,” added Mr. Springer of the Vanderbilt center. “This experiment is one step in the right direction in terms of building our knowledge base, but we need to continue to build that base and test other program designs.”

Saturday, September 11, 2010

Testing and miseducation. by Dr. Joseph A. Ricciotti

As we approach the beginning of a new school year, we find that education is in a crisis primarily due to the standardized testing mania that currently exists in the country. Teachers and parents need to ask themselves if the emphasis on testing and the time devoted to test preparation is helping to improve education, or whether education is being negatively impacted. Experts in the field of education such as Diane Ravitch, author of The Life and Death of the Great American School System, strongly believe the culture of testing, which began with 'No Child Left Behind' (NCLB) and is continuing with 'Race to the Top'(RTTT), is spreading through every school in the country. Ravitch believes the consequences of these misguided programs are "toxic" and students and teachers will suffer its consequences. She cites how most schools today devote far too much time to "drill and practice" in preparation for testing and not enough time to subjects such as history, science, the arts, geography and, as ridiculous as it may seem, even recess is being curtailed in many schools.

Likewise, the noted child growth and development specialist, Dr. David Elkind, author of Miseducation and The Hurried Child is very concerned about what is happening in many schools which are attempting to teach academic skills to preschoolers and kindergarteners as an outgrowth of test- driven instruction. As a result, he claims, we see many symptoms of stress in young children including headaches, learning problems, and even depression.

The pattern in schools across the country, both urban and suburban, is one in which Elkind describes as a "downward extension of the curriculum." In other words, what used to be taught in first and second grade is now being taught in kindergarten. This, in Elkind's words, is what he refers to as "miseducation" which, unfortunately for many children, can result in lifelong emotional disabilities.

Like all educational fads that come and go, the testing mania will soon be history. It is, without doubt, one of the worst educational fads to ever hit education and, unfortunately, with the present Secretary of Education, Mr. Arne Duncan, who is currently the most vociferous advocate of testing with his 'Race to the Top' program, it appears that testing will be with us longer than most teachers would have hoped for or anticipated. Duncan's misguided notion of education reform is based primarily on test scores and it is, indeed, a radicalized notion that even espouses evaluating teachers' classroom performance on the basis of how well their students perform on standardized tests. Ironically, Secretary Duncan is also proposing national standards and one would have to assume his rationale for national standards and tweaking tests to be harder would be that tests are better and more reliable if more children fail them.

Instead of this obsession with standardized testing, shouldn't we as educators and parents be questioning the entire concept of whether testing constitutes educational reform?

Hence, it is time for teachers to consider strategies in order to deal with the current sterile environment in education brought about asan outgrowth of NCLB and RTTT programs. Needless to say, it will be a very challenging and high-stakes battle as test-prone administrators, as well as local school boards, legislators and the State Boards of Education will place teachers in an adversarial position in this crucial struggle. It is critical for teachers to maintain a philosophical outlook that denigrates testing by attempting to spend a minimal amount of instructional time on this dastardly task in order to free up more time during the school day for real learning. Secondly, communicate with parents in your class the difference between test preparation,which is superficial learning based on facts, dates, etc., and real learning in which students learn how to think, research and develop a real love of learning. The only way teachers can overcome the pressures imposed on them by the testing zealots is to have parental support. Do you recall what happened in Scarsdale, New York when parents said “enough is enough” regarding time wasted on preparing students for testing and were able to put a moratorium on standardized testing. We need an army of parents collaborating with teachers who are vocal and who know that testing is bad for kids in order to help bring about real educational reform in this country. If enough parental support can be generated to rid the nation’s schools of the standardized testing burden, I guarantee that local school boards and politicians would change their tune.

And finally, we need to end what Secretary Arne Duncan is doing by financially rewarding states and school districts with additional funding who meet the goals of his misguided 'Race to the Top' program. His concept of reform is inequality at its worse and, in essence, many school districts, especially urban schools, who do not meet these rigid standards will only be made poorer. This is what happens when a non-educator is appointed to a position of educational leadership who doesn’t have the credentials or educational expertise that an educator in this position would have. Mr. Duncan's critics believe his leadership is based on fear, repression and punishment and that his policies are incompatible with the goals of public education. One would be naive to think that overturning the testing mania is an easy task as there are powerful interest groups that are leading the high-stakes testing game. As teachers and parents, we need to make our voices heard at the local level and we need to defend the concept of the neighborhood school. We must vehemently strive to rid education of the so called "top-down" type of leadership and educational decision making as reform can only be effective when grass roots are established and educational reform moves upward not downward. We must also preserve, at all costs, the sanctity of the neighborhood school concept. It is in the neighborhood school in which teachers and parents are empowered and where opportunities will be provided for decision making by teachers and parents who are closest to the child. This is truly the essence of sound educational reform.

Thursday, September 9, 2010

We Must Shift From Teacher Quality to Teaching Quality By Joseph Wise

Remarkable transformations in pre-K-12 education have occurred over the past 30 years; some have actually enriched schools and school systems by implementing systemic efficiencies. Others have served to heighten awareness of all that effective teaching actually entails. But many have been devastating. They have weakened the work being done in pre-K-12 classrooms, and set in motion certain practices and protocols that frankly undermine daily instruction.

Over a period of decades—decades of hard work and even greater posturing that ultimately resulted in the adoption of the federal No Child Left Behind Act—we have blurred an essential component of our work: accountability.

Accountability, at its essence, is not a goal; it is the acceptance of responsibility for all that we do in our classrooms, day in and day out. Accountability, when embraced for what it is, turns out to be not some sort of punitive “gotcha”; instead, it is what drives commitment to continuous examination, reflection, and improvement.

Despite the upside of accountability, we have failed to manage its unforeseen downside: a tendency to look back at regimented instruction with a sanitized fondness. It seems we have, in our profession, lost the will to acknowledge and leverage the multiple ways in which children learn—or to recognize the multiple ways children fail to learn when ineffective teaching is all that a classroom provides. We have, perhaps, become a nation of educators focusing wholly on the what of teaching, without effectively confronting the far messier (but pivotal) how of teaching.
"Accountability, at its essence, is not a goal; it is the acceptance of responsibility for all that we do in our classrooms, day in and day out."

No doubt content—the what in teaching—is essential. But we don’t teach in a vacuum. And it is evident that teaching centered solely on the content of what is being taught—while ignoring the how of delivering it effectively—is deadly. The practice enables us to reach only a fraction of students, and overlooks a fundamental reality: Our students continue to learn in diverse and different ways, often despite our well-intentioned efforts. The bottom line for us now is that accountability solely for the what of whatever is being taught is not enough, and ultimately impairs the very academic mastery we intend with students. If we are to make sustainable change in the lives of our students, we as educators have a baseline duty to establish accountability for how we are teaching.

This singular focus on the what has also led to interminable state and local debates about what academic standards are adopted, what assessments are valid and used, what curriculum is implemented, what data are analyzed, what policies are embraced—and, ultimately, what information is presented to our children. This one-dimensional approach to teaching and learning measures only one element of the equation, by focusing on content—a potent political and policy driver—in isolation from other essential elements. But deciding on and measuring only what is taught manifests a constant churn, and continues to conceal a fundamental flaw in the work we do.

We now largely discount or wholly ignore the how of teaching and how of learning. We measure and remeasure each school’s “adequate yearly progress.” We engage in benchmark testing, high-stakes testing, measurement of student population and population trends, measurement of students-per-class and students-per-employee; measurement of the number of impoverished students and numbers of racially identifiable students per school or district; measurement of special education services offered—the what measurement lists go on and on. Again, our work on and measurement in the what in teaching is not without merit; it simply is not enough. It never has been.

The Obama administration has made great strides toward correcting our federal funding deficiencies in pre-K-12 education. Bold leadership at the federal level, however, must be matched at the district and school levels with a committed focus on teaching as a practice.

Thoughtful leadership on the how of teaching is not entirely absent from our pre-K-12 teaching profession. But much of the leadership influencing how teachers teach has been narrowly focused, disjointed, and flat-out misguided. For us to effectively support our teachers and lead schools effectively, we must provide constructive, holistic, and behaviorally measurable guidance on how to engage students in the content being taught. By supporting and guiding teachers in the delivery of instruction, we ensure that classroom teaching will be not simply correlative to learning; it will cause learning.

Historically, intense focus on the what of teaching has led us away from a healthy balance of all that drives true academic achievement. How we teach, how we challenge, how we redirect, and how we engage students is of no less importance than the what we profess to teach. Ironically, over the years, we actually have learned much and documented much about best practices in teaching. Substantial and expert research reveals that we already have explored and analyzed much about the how of teaching; we simply haven’t acknowledged its pivotal effect on academic achievement in the way we support and coach teachers.

It is our duty as educators to ensure that teaching is powerful. And powerful teaching is as much about effective communication as it is about the content communicated. We as a profession have a compelling need to balance the what with the how in teaching, and to shift the argument away from teacher quality to teaching quality—for every child, in every classroom, every day.

Thursday, September 2, 2010

Should test scores be used AT ALL for teacher evaluation? By Valerie Strauss

Earlier this week a major report was released (pdf) saying that “value-added” formulas based on standardized test scores to evaluate teachers are unreliable and should not be used as a major factor in teacher assessment.

“Value-added modeling” has become the new big phrase in the education world. Essentially, it means measures that use test scores to track the growth of individual students as they progress through the grades to see how much “value” a teacher has added.

The value-added movement is supported by the Obama administration, which encouraged states to change laws to allow teachers to be evaluated primarily by such measures. And the Los Angeles Times recently used such a formula to grade more than 6,000 California teachers in a project that is highly controversial.

This would all be fine if assessment experts haven’t repeatedly warned that standardized tests designed for students should not be used to evaluate teachers. But they have. In addition, value-added formulas do not include other factors that affect students, and can skew results by giving better scores to teachers who “teach to the test” and lesser scores to teachers who are assigned students with the greatest educational needs.

In this climate, the Economic Policy Institute, a nonpartisan, nonprofit think tank based in Washington, the report, which concludes that heavy reliance on VAM methods should not dominate high-stakes decisions about teacher evaluation and pay.

The report, written by 10 prominent educators and researchers, says:

There is broad agreement among statisticians, psychometricians, and economists that student test scores alone are not sufficiently reliable and valid indicators of teacher effectiveness to be used in high-stakes personnel decisions, even when the most sophisticated statistical applications such as value-added modeling are employed.

For a variety of reasons, analyses of VAM results have led researchers to doubt whether the methodology can accurately identify more and less effective teachers. VAM estimates have proven to be unstable across statistical models, years, and classes that teachers teach.

And it warns of negative consequences if "value added" is a key component in evaluation -- including more “teaching to the test” and narrowed curriculum. Further, the study says, teachers may try to avoid being assigned particularly needy students because they do worse on standardized tests.

With all of that said, I wondered why the report did not say that these measures should not be used at all in evaluation.

The executive summary says:

Legislatures should not mandate a test-based approach to teacher evaluation that is unproven and likely to harm not only teachers, but also the children they instruct.

But it also says:

Adopting an invalid teacher evaluation system and tying it to rewards and sanctions is likely to lead to inaccurate personnel decisions and to demoralize teachers, causing talented teachers to avoid high-needs students and schools, or to leave the profession entirely, and discouraging potentially effective teachers from entering it.

So, what gives? Why should VAM measures be used if there is no consensus that they are reliable assessment tools? Why should they be given any weight? There are better, albeit more time-consuming ways, to weed out bad teachers.

I asked EPI to query the authors about this, and received a response from Helen F. Ladd, professor of public policy and economics at Duke University, president-elect of the Association for Public Policy Analysis and Management.

You can see the full list of authors, which includes Diane Ravitch and Linda Darling-Hammond, here, along with the executive summary.

I asked: If student standardized test scores are unreliable as stated in the study, why should they be used at all in teacher evaluation? Why doesn’t the study say they should not be used, period, for this purpose? Was the study bending to political reality?

Ladd: "There is no perfect way to evaluate teachers. Test scores are unreliable; so are principal observations, or peer evaluations, or analysis of videotapes, and so on. The only way to evaluate teachers fairly is to gather information from a variety of imperfect sources, each of which may contribute some information. If a teacher seemed to be ineffective in all of these measures, I’d be pretty confident that the teacher was ineffective. But if a teacher were ineffective only on one of them, I would be reluctant to make that conclusion.

"Test scores are unreliable, but they are still more often right than wrong, but not sufficiently more often to justify making high-stakes decisions on the basis of test scores alone. But giving test scores too much weight in a balanced evaluation system runs the additional danger of creating incentives to narrow the curriculum, as we described in the paper. If they are not given too much weight, this danger is lessened. How much weight they should be given should be a matter of local experimentation and judgment. All we say in the paper is that giving them 50 percent of the weight is too much."