Few topics cause as much debate and concern in education as teacher quality and effectiveness. Do teachers have a strong impact on a student’s performance? Can we measure this impact? How do we identify effective teachers?
Last month, the National Bureau of Economic Research published a working paper by researchers Raj Chetty, John Friedman and Jonah Rockoff that addresses these questions. The paper provides a detailed analysis of the effects teachers in large urban school district on both the test scores and long-term outcomes of their students. (Read the executive summary here or the full paper here). Building on the recent trend toward “value-added” measurements (which measures the average gain among students in a teacher’s classroom against the student’s prior test scores), the study included two major findings:
1) When a teacher who had high “value-added” scores joined a school, the test scores in the grade taught by that teacher would rise; when a high “value-added” scoring teacher left, the test scores would fall, and
2) Students assigned to high “value-added” scoring teachers tended to have more success on long-term measures, such as college attendance, salaries, and retirement savings.
On the whole, most of the reactions to the paper (such as CNN contributor William J Bennett and the New York Time’s Nicolas D. Kristoff) interpreted these findings as the strongest empirical evidence to date of the substantial impact teachers have on not only their students’ academic performance, but their futures as well.
Although the findings, as well as the amount of well-collected data supporting them, are undeniably crucial in demonstrating how great of an impact a teacher may have, some have cautioned against jumping to policy conclusions right away.
Considering the broad or specific recommendations based on these findings at this stage would not only be premature, but also skips over the more exciting impact of this study: the questions it raises about teacher efficacy and the path it sets out for research into teacher quality.
If this study has potentially provided a means of identifying excellent teachers, further research can use this technique to investigate other significant questions regarding teacher quality, such as:
- What qualities do high value-added teachers posses that distinguish them from their peers (what qualities make a teacher excellent)?
- Are there other methods for capturing and assessing information about these qualities for individual teachers? The study itself notes that using test scores to measure the performance of an individual would raise several problems (random error, cheating, teaching to the test, etc). However, it may be useful in validating other assessments of teacher performance that are more comprehensive or nuanced (such as observation tools).
- Which teacher education or preparation institutions tend to produce more high value-added teachers (and what do they have in common)? This issue seems poised to receive considerable attention in the coming year, particularly when the National Council on Teacher Quality releases its major study on teacher preparation programs this fall.
What impact do you think this will or should have on teacher assessment, preparation and practice? If this research does lead to a reliable measure of teacher efficacy, how could that affect teacher compensation or hiring and dismissal practices? How could school districts implement these strategies related to teacher efficacy? Are there any other questions or concerns this study raises? Share your reactions to the study below!