Good schools are synonymous with good teachers, but current methods of assessing teacher effectiveness are inadequate. Educators need a new approach to measuring teacher performance, consistent with new attention being given by policymakers to student academic outcomes. Such a shift will require an adjustment of the definition of good teachers, accompanied by changes in which aspects of teaching are considered important.
Today's view of teacher effectiveness relies on a static view of qualifications. Most states gauge teacher quality by input measures, what training a teacher possesses, or process measures, what activities or pedagogy a teacher delivers. These measures do not correlate well enough with student academic gains to be trusted as a way to assess teachers. Worse, each teacher who passes the minimum threshold is considered equivalent to any other, a commodity approach that serves them and their students poorly.
Instead, we must begin evaluating teacher effectiveness on the basis of the direct impact that teachers have on student achievement. Whatever else a teacher may provide, we need teachers who can "deliver the goods" in terms of moving their students ahead academically.
Only by assessing student outcomes can we get a clear measure of teacher performance. In concept, this solution seems straightforward. But we must be able to link students to their teachers and examine the impact a teacher has had on his or her students over the course of several years. Such associations require a unique teacher identification number, which is currently absent in many states.
At the same time, it would be irresponsible to treat the academic gains a teacher creates in a year's time as the sole factor in determining an individual teacher's effectiveness. Existing research indicates that other factors also contribute to student learning gains, such as prior achievement and family and peer characteristics. Simple aggregations of student gains should not be relied on as a solitary measure of teacher performance.
What is needed is a way to separate the important contributions that teachers make from family, school, and other influences. It is unfair to attribute everything that goes on in schools to teachers. But our current school accountability programs do not separate the role of teachers from such things as how closely aligned a district's curriculum is to state academic standards, turnover in staffing, or new administrative leadership. Although we currently know little about the interplay of these effects, we will need to better understand them to know which factors amenable to public intervention hold the best promise for improvements in our schools.
Two related changes are necessary. First, states need unique teacher identification numbers (similar to those for students) that follow them throughout pubic school service, thus enabling analyses of the value of resources and their returns on improving student education outcomes. Evaluation of curricular programs, teacher development, and new reform programs are then immediately within reach, resulting in more informed decisions about school spending. In this time of budget constraints, any means to better target existing resources is a boon.
Second, all states need to expand their data on students and teachers so that the underlying relationships among student, school, family, and teacher factors can emerge.
These vitally needed steps are missing from the good-faith efforts under way to improve our schools. For further information visit credo.stanford.edu.
