Ninth and 10th graders in the Miami-Dade County school district whose math teachers were certified by the National Board for Professional Teaching Standards scored slightly higher than other students on a Florida mathematics exam, a study finds.
The study by the CNA Corp., a research organization in Alexandria, Va., was conducted by reviewing roughly 108,000 student records from the district from the 1999-2000 and 2002-03 school years.
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鈥淚n this study, [national-board certification] proved to be an effective signal of teacher quality,鈥� writes Linda C. Cavalluzzo, the author and chief investigator for the study. 鈥淭o increase student outcomes in the nearer term, the challenge for school systems will be to implement professional-development programs or strategies that change practices so more teachers will adopt methods used by those who have already earned [board certification].鈥�
Student records were linked to students鈥� subject-area teachers, and that information was used to set up a vast database of teacher and student characteristics. A teacher鈥檚 number of years in the classroom, whether he or she had an advanced degree, whether a student was identified as gifted, and if a student was repeating a grade were among the pieces of information included.
When the researcher looked at students鈥� scores on the Florida Comprehensive Assessment Test, she found that teachers who had earned NBPTS certification were more effective at raising achievement than teachers with other attributes. Specifically, the 鈥渆ffect size鈥� for a national-board-certified teacher was .07, which is statistically significant. For comparison, the effect size for a teacher with a graduate degree was .017, and for a teacher with a state high school certification, it was .06.
Black and Hispanic students appeared particularly to benefit from having board-certified teachers, according to the study. With those students, the effect sizes were about .15.
The most effective teachers had a combination of characteristics: national-board certification, a state certificate in mathematics instruction, and teaching assignments in math alone.
In an interview, Ms. Cavalluzzo called NBPTS certification a 鈥渘ice, new important signal鈥� that officials can use to identify and reward successful teachers.
Of the 2,000-some Miami-Dade teachers examined, 61 had already earned the credential, 101 were in the application process, eight had failed, and 10 had withdrawn from the program. The others had not engaged in the process.
Worth the Cost?
But some scholars question whether the credential is making a big enough difference in the classroom.
鈥淚s this what policymakers thought they would be getting when they committed to a 10 percent salary increase and a $5,000 bonus?鈥� said John E. Stone, an education professor at East Tennessee State University in Johnson City, who has conducted his own research on national-board certification. 鈥淧lainly, having all [board-certified] teachers would make little difference relative to the magnitude of the problem.鈥�
The new study, underwritten by the National Science Foundation, is the latest in a series of research projects that the Washington-based national board has commissioned in an effort to determine whether nationally certified teachers are helping to raise student achievement.
Previous research has shown more significant gains for students with such teachers. (鈥淔irst Major Study Suggests Worth of National 鈥楽eal鈥�,鈥� March 17 and 鈥淎riz. Study Sees Benefits in National-Board Certification,鈥� Sept. 15, 2004.)
The CNA study, however, is the first to focus on the effects of the credential on high school students.
