The National Board for Professional Teaching Standards (NBPTS) certification is an advanced teaching credential that complements (and does not replace) state certification. This analysis estimates the effects elementary school students experience from having been taught by a NBPTS-certified teacher.

Teachers earn NBPTS certification upon completion of a one- to five-year assessment process. The assessment process requires applicants to complete one general skills exam and three portfolios demonstrating their teaching ability and content knowledge. Washington State provides an annual salary bonus to NBPTS-certified teachers. Some NBPTS-certified teachers working in qualifying high-poverty schools can also receive an additional annual bonus.

 

Meta-analysis is a statistical method to combine the results from separate studies on a program, policy, or topic to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The outcomes measured are the program impacts measured in the research literature (for example, impacts on crime or educational attainment). Treatment N represents the total number of individuals or units in the treatment group across the included studies.

An effect size (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases. See Estimating Program Effects Using Effect Sizes for additional information on how we estimate effect sizes.

The effect size may be adjusted from the unadjusted effect size estimated in the meta-analysis. Historically, WSIPP adjusted effect sizes to some programs based on the methodological characteristics of the study. For programs reviewed in 2024 or later, we do not make additional adjustments, and we use the unadjusted effect size whenever we run a benefit-cost analysis.

Research shows the magnitude of effects may change over time. For those effect sizes, we estimate outcome-based adjustments, which we apply between the first time ES is estimated and the second time ES is estimated. More details about these adjustments can be found in our Technical Documentation.

Meta-Analysis of Program Effects
Outcomes measured	Treatment age	Primary or secondary participant	No. of effect sizes	Treatment N	Effect sizes (ES) and standard errors (SE)			Unadjusted effect size (random effects model)
					ES	SE	Age	ES	p-value
Suspensions/expulsions In-school suspensions, out-of-school suspensions, or expulsions from school	10	Primary	4	20605	0.001	0.001	10	0.001	0.487
Test scores Standardized, validated tests of academic achievement.	10	Primary	17	405356	0.021	0.005	10	0.021	0.001
School attendance Number or percentage of school days present in a given enrollment period.	10	Primary	4	20605	0.045	0.021	10	0.045	0.030

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Manzeske, D., Park, S.J., Liu, F., Borman, T., Gnedko-Berry, N., West, B., & Deng, E. (2017). Effects of National Board Certified Teachers teachers on student achievement and behavioral outcomes: Studies conducted in two states. Working Paper. American Institutes for Research.