National Certification Doesn’t Reward Best Teachers, Studies Show

Published May 1, 2005

When K-12 public school teachers attain certification through the National Board for Professional Teaching Standards (NBPTS), they are rewarded with annual bonuses of up to $7,500. Yet four value-added research studies conducted since 2002–including three sponsored by NBPTS itself–have shown NBPTS-certified teachers produce only small gains in student achievement.

That raises questions about whether the bonuses for NBPTS certification are being misdirected to average teachers, instead of going to teachers who produce substantial gains in student achievement.

“The differences in achievement gain between NBPTS-certified teachers and those not certified are so small as to be barely detectable,” said J.E. Stone, an educational psychology professor at East Tennessee State University who conducted one of the value-added studies. “The people who are trying to convince policymakers that those differences represent an educationally important advantage are misrepresenting the available evidence.”

NBPTS Research Director David Lussier strongly disagreed with Stone’s view, pointing out the independent researchers themselves had identified their results as “robust” and “significant.”

“If you read their studies,” Lussier said, “[the researchers] are quite consistent in saying, ‘We have found gains and the National Board does seem to be certifying the most effective teachers.'”

Additional Questions Raised

Additional questions about NBPTS certification have been raised by a new analysis of the value-added data by Stone and George K. Cunningham, an educational psychology professor at the University of Louisville.

Their analysis shows the top 10 percent of ordinary classroom teachers in North Carolina–those without national certification–produce student achievement gains 10 to 20 times larger than those produced by teachers with NBPTS certification. Under the uniform salary scale, these top teachers receive no additional pay for their exceptional work.

“It would seem that the educational objective of increasing measured student achievement would be far better served by a policy of rewarding the teachers who produce the highest levels of achievement gain than by encouraging NBPTS certification,” Cunningham and Stone conclude.

Alternatives Far Less Expensive

Whereas the cost of attaining NBPTS certification is substantial–a fee of $2,300 per teacher, plus an estimated 150 to 200 hours of uncompensated preparation time and a 50 percent failure rate–Cunningham and Stone note the cost of value-added assessment of teacher effectiveness would be far less, at approximately $1 per student and $25 per teacher. In addition to assessing teacher effectiveness, the value-added process would produce measures of district, school, and individual student performance.

“A policy of awarding bonuses to teachers who meet or exceed the 90th percentile of local district gains would not only eliminate the awkward possibility of misdirected awards, it would ensure that all teachers who were doing truly exceptional work are rewarded for their talents and effort,” the authors conclude.

Lussier maintained that independent research studies had consistently shown the National Board was certifying the right teachers.

“The value of National Board certification is much broader than what’s going to be measured in a standardized test,” Lussier said. “Standardized tests, in and of themselves, measure a particular set of knowledge and skills that may not represent the full array of value that students are gaining from having highly effective teachers.”

Student Achievement Downplayed

While NBPTS’s national certification standards express the organization’s view of an accomplished teacher’s capabilities, the standards contain no explicit link to student achievement, nor do they address the role high-quality teachers play in raising student achievement or closing the achievement gap between students from low- and high-income families. According to Cunningham, this lack of emphasis on student achievement grows out of an educational philosophy that does not regard academic achievement as overwhelmingly important.

Lussier said NBPTS viewed standardized test scores as “only one measure” of student achievement, but he contended the research studies had established the connection between NBPTS certification and test scores.

“We think that those effect sizes are large enough,” he said. “The researchers define those as ‘significant.'”

Trivial Effects Called “Robust”

In late 2001, under pressure to prove NBPTS-certified teachers have a positive effect on student achievement, the board commissioned a series of value-added studies to determine the effect of certification on student test scores. Four studies have been completed to date.

Though the study conducted independently by Cunningham and Stone shows results similar to those commissioned by the NBPTS, it is the only one to characterize the gains as trivial, rather than “robust.” A separate analysis conducted by Cunningham suggests students’ scores actually fall while their teachers are going through the NBPTS certification process and using its “best practices.”

“There is really no reason to think NBPTS teachers will have students with higher academic achievement, because this certification mandates that one disavow the importance of academic achievement and discourage the use of instructional methods that have proven effective in increasing academic achievement,” Cunningham said.

Teachers’ Importance Examined

Studies by SASinSchool statistician William L. Sanders and other researchers have shown individual teachers can have a dramatic effect, both positive and negative, on student learning. Hoover Institution economist Eric Hanushek has shown top teachers can attain a full year of additional learning for their students compared to lower-performing teachers, with a good teacher annually adding 1.5 grade-level equivalents for his or her students and a bad teacher adding only 0.5.

At a 2003 Brookings Institution conference, Hanushek and Steven Rivkin of Amherst College argued good teachers can overcome deficits in a student’s home environment. They estimated that if children from lower-income families had five consecutive years of good teachers, it would close the seventh-grade mathematics achievement gap between those children and their peers from higher-income families.

“In other words, high-quality teachers can make up for the typical deficits we see in the preparation of kids from disadvantaged backgrounds,” Hanushek and Rivkin said. “If one is concerned about student performance,” they added, “one should gear policy to student performance.”

Standardized Tests Ignored

A “good” teacher, as defined by Hanushek and Rivkin, is one whose students show achievement gains of 100 percent of a standard deviation above average. According to Cunningham and Stone’s analysis of the four value-added studies, NBPTS-certified teachers perform very poorly against that standard, producing achievement gains of only about 8 percent of one standard deviation, only slightly larger than those produced by their non-certified colleagues. (See accompanying graph.)


However, Lussier argued, “Standardized test scores in and of themselves do not close the achievement gap, do they? All they do is provide data.” Questioning how measuring test scores could change teaching practices, he said, “Unless there’s some kind of intervention, some kind of system, by which those data are used in a purposeful way, the data in and of themselves don’t improve achievement.

“Our position is the National Board certified teachers are not only helping to raise student achievement but we know how they’re doing it as well,” Lussier said. “They’re meeting a set of standards that has through a wide consensus been seen as providing the most comprehensive definition of what accomplished teachers should know and be able to do.”

George Clowes ([email protected]) is associate editor of School Reform News.

For more information …

George K. Cunningham and J. E. Stone, “Value-added assessment of teacher quality as an alternative to the National Board for Professional Teaching Standards: What recent studies say,” in Robert Lissitz (ed.), Value added models in education: Theory and applications (Maple Grove, MN: JAM Press, in press), is available online at

Eric A. Hanushek and Steven G. Rivkin, “How to Improve the Supply of High Quality Teachers,” in Diane Ravitch (ed.), Brookings Papers on Education Policy 2004 (Washington, DC: Brookings Institution Press, 2004), pages 7-25, is available online at