Conducted by Geoffrey Borman and Steven Kimball.
Purpose of study
To determine whether teacher evaluation scores explain differences in achievement for students with different prior achievement scores and social backgrounds and to explore the distribution of teacher quality (as measured by the teacher evaluation system) among classrooms.
- Is teacher quality distributed equally across classrooms of varying compositions?
- Is teacher quality associated with both excellence and equality in terms of student achievement?
The researchers used teacher evaluation scores, student demographic and student achievement data from the Washoe County School District in Nevada, which implemented a teacher evaluation system based on Charlotte Danielson’s Framework for Teaching (FFT) in 2000. Teachers with sufficient observational data to create a composite score for the four domains of the FFT (N = 397) and their 4th, 5th, and 6th grade students (N = 7,335) were included in analyses.
- Teachers in classrooms with a high concentration of students receiving free or reduced-price lunches tended to have lower evaluation scores. On average, these teachers scored half of a standard deviation lower on the FFT composite score than teachers whose classrooms contained few or no students who received free or reduced-price lunches.
- Teachers in classrooms with a high concentration of minority students also tended to have lower evaluation scores. These teachers also scored half a standard deviation lower on the composite evaluation score, on average, than their peers teaching primarily white and/or Asian American students.
- Classrooms composed students with lower pretest scores in reading and math were also largely taught by teachers who received lower evaluation scores than teachers of high-achieving students, by a similar magnitude.
- Hierarchical linear models found that the effect of teacher quality on student achievement varied by subject (math or reading) and grade level. On average, a “good” teacher (with an evaluation score 1 standard deviation above the mean, or at the eighty-fourth percentile of the distribution) raised student achievement one fifth of a standard deviation higher than a “bad” teacher (with an evaluation score 1 standard deviation below the mean, or at the sixteenth percentile in the district).
- Overall, “equalizing” effects, or the ability of teachers with higher evaluation scores to close achievement gaps between more and less privileged students, were close to zero. However, results of the model for 4th grade reading classes indicated that higher-quality teachers made some progress in closing the achievement gap separating poor and nonpoor students.
While results suggest that disadvantaged students are systematically assigned to lower-quality teachers, it is also possible that teachers of disadvantaged students are rated lower because of the characteristics of their students. The authors also propose that school context, such as limited capacity or a weak professional culture, may constrain the performance of otherwise good teachers, and points out that each interpretation has different implications for equality of educational opportunity, the evaluation system, and school organizational processes.
Approximately 75% of the variation in student achievement occurred within classrooms. Thus, while “good” teachers raised the overall achievement of their students more than “bad” teachers did, the “good” teachers did not reduce gaps between their highest- and lowest-achieving students’ test scores. If teacher quality is expected to include the ability to close achievement gaps between more and less privileged students, this aspect of teacher quality may not be reflected by the composite score used for this study. The authors recommend placing greater emphasis on 22 rubrics across the four domains of the evaluation system that relate to closing achievement gaps and promoting training and professional development opportunities to enhance multicultural awareness and educational equity.
The teacher evaluation system in Washoe County, Nevada, is based on the Framework for Teaching, so results associating those teachers’ evaluation scores with student achievement and the potential to close achievement gaps validates that the Framework is measuring teacher quality.