Teacher Quality and Student Achievement

Research Q & A: Teacher Quality And Student Achievement

1.  How important is teacher quality to raising student achievement?

A growing body of research shows that student achievement is more heavily influenced by teacher quality than by students’ race, class, prior academic record, or school a student attends. This effect is particularly strong among students from low-income families and African American students.

The benefits associated with being taught by good teachers are cumulative. Research indicates that the achievement gap widens each year between students with most effective teachers and those with least effective teachers. This suggests that the most significant gains in student achievement will likely be realized when students receive instruction from good teachers over consecutive years.

2.  How can attention to teacher quality close achievement gaps—the tendency for some groups of students to achieve less academically than others?  

Poor and minority students are the least likely group to be taught by teachers with experience, knowledge, and credentials, the elements of teacher quality that research demonstrates are strongly associated with high student achievement. Research also shows that these students produce the most gains when assigned to effective teachers. Indeed, these findings have led many researchers and analysts to assert that the lack of good teachers is a major contributor to the achievement gap.

A California study suggests that schools hit a “tipping point” when approximately 20 percent of the school faculty is comprised of underqualified teachers—teachers who do not meet minimum state requirements. After this point, schools begin to lose their ability to improve student achievement. The best strategy for closing achievement gaps is to make sure that schools serving poor and minority students have their fair share of qualified teachers.

3.  What is meant by “value-added”?  

Value-added is a measure of change, or effect, brought about by a certain action. When the subject is teaching, the value-added is the amount of students’ academic growth produced by a teacher.

The most compelling evidence for the importance of teacher quality initially came from economists who adapted value-added models from business to measure the effect of teachers on student learning. While the statistical methods are complex, the definition of effective teaching is not. Simply, researchers looked for the change in students’ test scores according to the teacher they were assigned to. A highly effective teacher, therefore, is one whose students show the most gains from one year to the next.

By using a value-added approach, researchers are able to isolate the effect of the teacher from other factors related to student performance (e.g., students’ prior academic record, school they attend, or family circumstances).

4.  What are the qualities of an “effective teacher”? 

Research findings point to four key dimensions of teacher quality:

• Content knowledge. 

• Teaching experience. 

• Professional certification. 

• Overall academic ability.

It’s important to note that there are individual teachers who are highly effective although they lack one or more of these qualities, just as there are ineffective teachers who have all of them. But on average, the presence rather than absence of these qualities is more likely to produce effective teaching.

5.  How important is teachers’ content knowledge?

Researchers agree that teachers’ content knowledge influences student performance. Many studies support the notion that teachers who teach subjects that they have previously studied in depth (by earning a major or minor in the field while in college or earning an advanced degree in the discipline) are particularly effective. However, advanced degrees in general—degrees that are not in the subject matter being taught—have not been found to be associated with higher student achievement.

Research is not yet clear about the magnitude of the effect of teachers’ content knowledge relative to other important teacher attributes.