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Why Excellent Teaching Matters and What it Looks Like

Why Excellent Teaching Matters

There are not many who, when given an option, would choose to have a poor classroom teacher rather than a good one. But just how important is the teacher to student achievement and learning? Researchers are finding that the effect of good teaching is substantial and lasting. Perhaps the most well known research on this question was performed by William L. Sanders and June C. Rivers at the University of Tennessee. In one study, they found that "groups of students with comparable abilities and initial achievement levels may have vastly different academic outcomes as a result of the sequence of teachers to which they are assigned" (1996). Three years of highly effective teachers can boost student achievement by as much as 50 percentile points, compared to having relatively ineffective teachers for three years. Sanders' research examines "the improvement of students from the beginning of the school year to the end" based on test scores (Carey, 2004, emphasis in original), what is called the "value added" by teachers. Several studies have been conducted using a value-added approach. In "Good Teaching Matters... A Lot", Kati Haycock of The Education Trust reviewed value-added research in Tennessee, Dallas, and Boston. In Boston, Haycock notes that the top third of effective teachers "are producing six times the learning seen in the bottom third" (1998).

Such differences in effects on student performance on standardized tests are impressive, but what do the numbers mean? In an often cited study, Eric Hanushek of Stanford University reports "the estimated difference in annual achievement growth between having a good and having a bad teacher can be more than one grade-level equivalent in test performance" (1992, emphasis in original). In fact, classroom teachers contribute more to student achievement than any other factor. Specifically, Sanders' value-added research found that teacher effectiveness has a greater impact than "race, poverty, [or] parent's education" (Carey, 2004). In addition, Linda Darling-Hammond, from Stanford University, notes in a research review that differences in teacher effectiveness are more important than "differences in class size" (2000). Darling-Hammond's own analysis of data from the National Assessment of Educational Progress found "that the effects of well-prepared teachers on student achievement can be stronger than the influences of student background factors, such as poverty, language background, and minority status" (2000). Finally, John Schacter from the Milken Family Foundation and Yeow Meng Thum from UCLA found in a review of relevant studies that "When compared to virtually every other school reform effort to date (e.g. class size reduction, charter schools, vouchers, direct instruction, technology, etc.), students who have effective teachers achieve the most" (2004). The quality of the teacher, then, is the most important school-related factor and can be more powerful than many out-of-school factors.

Characteristics of Effective Teachers

What the studies cited so far do not tell us, however, is what makes teachers effective. More recent research has attempted to answer this question by pairing value-added research methods with studies of teacher characteristics. Not surprisingly, there is not universal agreement among researchers about which teacher qualities matter the most. However, several research reviews have identified teacher qualities that seem to make a difference:

The four attributes discussed above are the most commonly studied because they are the easiest to measure. Other teacher qualities may be as or more important, but are difficult to measure on a large scale. For example, Walsh and Tracy suggest that the qualities that Teach for America has found to be common among their most successful teachers (academically successful in school and college, responsible, able to think critically, motivated, respectful, and sharing the organization's goals) may be important contributors to teacher effectiveness. Similarly, Linda Darling-Hammond identifies a "positive relationship between student learning and teachers' 'flexibility', 'creativity', or 'adapatability' ...Successful teachers tend to be those who are able to use a range of teaching strategies and who use a range of interaction styles, rather than a single rigid approach" (2000). Such "soft" attributes are undoubtedly important, but they are difficult to ascertain without observing or interviewing teachers directly.

Quality Teaching

The research on teacher characteristics and their effect on student achievement has been useful in recent discussions about how to construct policies to encourage high quality teachers to enter and remain in the profession. However, it is most likely that the positive effects on student achievement attributed to good teachers are as much a result of quality teaching as of teacher qualities. In other words, it is how teachers teach that makes the most difference in student achievement. Like the personality traits mentioned above, however, how teachers teach is more difficult to measure than how many years someone has been a teacher. In fact, CFTL notes that "there are no comprehensive reviews that neatly synthesize research on teaching practices" (2007). Rather than relying on research reviews, then, this section summarizes a few studies that attempt to identify effective teaching practices as measured by effects on student achievement.

In a 2005 study, Geoffrey D. Borman and Steven M. Kimball of the University of Wisconsin sought to determine "whether high-quality teaching was related to better outcomes for all children" using data from more than 7,000 students and almost 400 teachers. To determine teacher quality, they relied on classroom observations by a teacher's principal or assistant principal, using a set of standards for teachers. The standards in the study dealt with teachers' content knowledge, use of a variety of instructional methods, lesson planning, use of assessment data, adaptivity to student needs, persistence, and engaging "students cognitively in activities and assignments ...congruent to instructional objectives." The researchers examined student performance data in grades 4-6 in math and reading. After accounting for other factors, such as "teacher experience and student pretest score, minority status, and free-lunch status," Borman and Kimball found that "better teaching appears to be related to better learning outcomes." In other words, teachers who were rated highly according to the standards produced better results for kids.

John Schacter and Yeow Meng Thum used a similar approach to measuring teacher practice and its effect on student achievement in a 2004 study of more than 50 teachers at five Arizona elementary schools. Schacter and Thum developed "12 teaching performance standards and rubrics to assess teaching quality." Their standards were drawn from a comprehensive review of research on "teacher behaviors, teaching models, teaching strategies and teacher qualifications." The standards included such practices as:

Participants were evaluated on their use of those 12 practices during eight observations. The results of their findings are clear: "teachers who implement effective teaching as measured by our 12 teaching standards and performance rubrics produce students who make considerable achievement gains."

As demonstrated by the two studies discussed above, measuring the effect of teacher quality through an observation of classroom practice is a labor intensive process. One way that researchers have dealt with this is by studying teachers who are already identified as excellent through some other method. For example, many studies have measured the effects on student achievement of teachers certified by the National Board for Professional Teaching Standards (NBPTS).1

The NBPTS seeks to "advance the quality of teaching and learning by developing professional standards for accomplished teaching, creating a voluntary system to certify teachers who meet those standards and integrating certified teachers into educational reform efforts" (NBPTS website). Teachers achieve board certification based on portfolios of student work and videos of the applicants teaching and also on their score on a test of their subject-matter knowledge. They are evaluated on:

So, are nationally board certified teachers the most effective? Dan Goldhaber of the University of Washington and Emily Anthony of the Urban Institute set out to answer this question in 2004 by comparing the effectiveness of board-certified teachers against teachers who had tried to become certified but did not make it. They found that "teachers who are successful in their attempts to attain certification are more effective than those who are unsuccessful applicants, providing evidence that NBPTS is, in fact, identifying the more effective teachers of those they actually evaluate." In addition, those who are or eventually become board-certified are more effective than those who do not meet the selection criteria or who do not apply. In another study from 2004, Leslie Vandevoort, Audrey Amrein-Beardsly, and David Berliner from Arizona State University confirmed these findings. They concluded that students in the classrooms taught by board-certified teachers outperformed students in classrooms with non-board certified teachers 100% of the time. Thus, the qualities of effective teaching identified by the National Board appear to be teaching practices that have a positive impact on student achievement.

Finally, the authors of the CFTL research review on effective teaching offer five "key themes ...that reflect key findings from the research" on teaching practices. The five themes are:

Interestingly, each of these themes finds some support in one or more of the studies summarized above. In other words, all of these teaching practices have been demonstrated, to one degree or another, to have a positive effect on student achievement as measured by student performance on standardized tests.


While these studies have identified important characteristics and practices of effective teachers, teaching occurs in a complex environment. Many factors contribute to student achievement, and while the quality of the teaching is the most important school factor in student achievement, teaching quality itself is affected by contextual factors. For example, Yvonne Goddard, Roger Goddard, both of the University of Michigan and Megan Tschannen-Moran of the College of William and Mary found that "fourth-grade students have higher achievement in mathematics and reading when they attend schools characterized by higher levels of teacher collaboration" (2007). It may be the case, then, that effective teachers will be even more effective in a collaborative workplace (or less effective in a dysfunctional environment).

Finally, as many have noted before, standardized tests are not the only measure of student learning or the effects of a good teacher. Standardized tests may not be the best measure of critical thinking, writing, or creativity. Nor do they typically measure what may in fact be the most important result of an excellent teacher, instilling a lifelong love of learning in students. Inspiration, curiosity, an ability and desire to pursue knowledge: the best teachers provide all of these to their students, and yet these effects are not measured on the SAT. In the end, the importance of quality teaching in our classrooms may be beyond measure.

Bibliographic information for the research studies cited in this document can be found in the Research on Teaching section of this website.

1. Not all of the studies have found positive results, but NBPTS claims on their website ( that a majority of the more than 150 studies "found NBCTs make a significantly measurable impact on teacher performance and student learning, engagement and achievement."