Is evaluating teachers an exact science? Many people — including many teachers and their unions — believe current methods are often too subjective and open to abuse and misinterpretation. But new tools for measuring teacher effectiveness have become more sophisticated in recent years, and several large-scale studies in New York, Los Angeles and North Carolina have given those tools more credibility. A new study released on Monday furthers their legitimacy; and as the science of grading teachers advances, it could push for further adoption of these tools.[…]
And there is a broader point in favor of CFR’s work: Their numbers are being replicated in many different settings. Even in Rothstein’s paper critiquing their method, he replicated their results using data from North Carolina public schools. “I’m not aware of another area of social science where there has been so much replication, in such a short time, and they’ve all found the same result,” Kane said. On the consistency of replicability, Staiger said “it’s just astounding, actually.” Even Rothstein grants this: “Replication is an extremely important part of the research process … I think this is a great success, that these very complex analyses are producing similar results.”
“It’s almost like we’re doing real, hard science here,” Friedman said. Well, almost. But by the standards of empirical social science — with all its limitations in experimental design, imperfect data, and the hard-to-capture behavior of individuals — it’s still impressive. The honest, respectful back-and-forth of dueling empirical approaches doesn’t mean the contentious nature of teacher evaluation will go away. But for what has been called the “credibility revolution” in empirical economics, it’s a win.