It is common knowledge that teacher quality is a key in-school factor affecting student achievement. While the quality of teaching clearly matters for how much students learn, this quality is challenging to measure. Evaluating teacher quality based on the level of their students' end-of-year test scores has been one method of assessing…

Value-added models measure teacher performance by the test score gains of their students, adjusted for a variety of factors such as the performance of students when they enter the class. The measures are based on desired student outcomes such as math and reading scores, but they have a number of potential drawbacks. One of them is the…

There are good reasons for re-thinking teacher evaluation. Evaluation systems in most school districts appear to be far from rigorous. A recent study showed that more than 99 percent of teachers in a number of districts were rated "satisfactory," which does not comport with empirical evidence that teachers differ substantially from each other in…

Value-added models have caught the interest of policymakers because, unlike using student tests scores for other means of accountability, they purport to "level the playing field." That is, they supposedly reflect only a teacher's effectiveness, not whether she teaches high- or low-income students, for instance, or students in accelerated or…

The writer examines a variety of reasons why test performance may not always be a valid measure of a person's competence or potential. Citing that a sizable percentage of students perform well in their schoolwork but poorly on standardized, multiple-choice tests, Bond defines and discusses four candidates as source factors for the phenomenon: (1)…