RALEIGH — Is it possible to measure teacher effectiveness? For decades, public school principals have subjected teachers to a battery of observations and evaluations purportedly designed to assess the quality of classroom instruction. Rather than yield appreciable information, however, these kinds of teacher assessments merely served as one of the few formal requirements needed to attain lifetime job security, also known as tenure.
On the other hand, the “value-added” method of teacher evaluation continues to show promise as an objective and reliable assessment of teacher quality. Value-added analysis uses standardized tests to estimate teacher effectiveness. This powerful evaluation method employs advanced statistical techniques to project the future performance of individual students based on their past performance. The difference between the projected and actual performance of students determines the value added or subtracted by the teacher.
Value-added analysis has upended the conventional wisdom on teacher quality. For years, public school advocacy groups complained that the most talented teachers snub minority and low-income schools by migrating to less challenging and higher paying schools in culturally and economically homogeneous suburbs.
Nevertheless, according to a recent analysis of value-added scores for teachers in the Los Angeles Unified School District, the district’s best elementary school teachers shared few common traits. The top teachers had none of the common metrics used to determine teacher quality (e.g. age, years of experience, education level, instructional method, or student demographics) in common. What they did have in common was the ability to raise student achievement far above expectations.
These facts raise serious questions about the continued use of state salary schedules, which reward teachers based on years of experience, advanced degrees, credentials, or additional duties. Value-added analysis suggests that the current system does not select and reward talented teachers or preclude ineffectual teachers from remaining in the classroom.
Public school systems in North Carolina and beyond should move to a more effective compensation system that uses transparent, outcome-based measures, including test scores and value-added measures, to reward the efforts of individual teachers and administrators.
For the last four years, the N.C. Department of Public Instruction has maintained a sophisticated educational value-added assessment system (called EVAAS), so this kind of performance pay arrangement would come at no additional cost to taxpayers.
So why do education leaders in North Carolina refuse to expand the use of EVAAS? Since the start of North Carolina’s testing program in 1996, it has been common practice for the state’s public school systems to gauge school and teacher quality by simply comparing school-wide test score results to statewide averages or trends.
By design, the school-wide approach offers little information about the performance of individual teachers within the school, thereby allowing inept teachers to lie low in an otherwise good school. Of course, such cover is often a double-edged sword for the teachers themselves because it also obscures the achievements of good teachers in poorly performing schools.
Making matters worse, state education officials and school superintendents have worked together to restrict access to the state’s value-added information.
In a recent interview with National Public Radio, Donald Martin, superintendent of the Winston-Salem/Forsyth County School District, praised the State Board of Education for maintaining a policy keeps value-added assessment of teacher performance under wraps. Their shared goal is to protect teachers from public scrutiny, an effort that keeps vital information away from parents and maintains the good graces of status quo advocacy groups like the North Carolina Association of Educators.
Public school districts should make value-added information readily available to parents, regardless of how much the information would upset the status quo. It would encourage parents to demand that schools place their children in the classes taught by the most effective teachers. And the only way to achieve these demands would be to grant parents the information and educational choices they deserve.
Terry Stoops is director of education studies at The John Locke Foundation.