A new study claims to have found evidence of what has long been something of a missing link in the quest for school improvement: ties between state policies on teacher quality and statewide student performance.
Carried out by Linda Darling-Hammond, an education professor at Stanford University, the analysis shows that a state’s percentage of qualified teachers is one of the strongest predictors of its students’ improvement on the National Assessment of Educational Progress. A paper based on the study is in this month’s Education Policy Analysis Archives, an online journal based at Arizona State University’s college of education.
Follow-Up |
| “Teacher Quality and Student Achievement: A Review of State Policy Evidence” can be found at epaa.asu.edu/epaa/v8n1/. A summary is available for free by calling the Center for the Study of Teaching and Policy at (206) 221-4114. |
“There does seem to be some interesting connections between the qualifications of teachers and the level of student achievement in states and between what states do as policy entities and their overall quality of teachers,” said Michael S. Knapp, a professor of education and the director of the Center for the Study of Teaching and Policy at the University of Washington. “If those two links are the case, that’s news.”
Mr. Knapp’s center was a sponsor of the study.
Looking for Linkages
In recent years, quantitative studies have begun to confirm the common-sense notion that teacher quality is an important factor in determining a child’s academic success. In particular, much attention has been paid to the work of the University of Tennesee’s William L. Sanders, who has studied the “value added” effects of schools and teachers. (“Sanders 101,” May 5, 1999.)
But few large-scale studies have examined what characteristics make up an effective teacher, and even fewer have attempted to show which policies yield enough highly qualified teachers to make a difference in a state’s student-test results.
Using a statistical tool called regression analysis, Ms. Darling-Hammond examined federal databases of teachers’ qualifications and student performance, as well as surveys of state policies carried out by the National Commission on Teaching & America’s Future, which she directs. The aim was to discover which of several factors best predicted improvement on NAEP, the federally sponsored sampling of students in core subjects, from 1992 to 1996.
Of those examined, the best predictor was the proportion of a state’s teaching force who were well qualified, which Ms. Darling-Hammond defined as an educator possessing both a full teaching license and at least a college major in the subject taught. Those two qualifications were even more strongly related to NAEP gains than per-pupil spending, class size, and students’ socioeconomic status.
Ms. Darling-Hammond then went on to look for relationships between specific state policies and the percentage of fully qualified teachers in states. She found, for example, correlations between the level of teachers’ qualifications and the existence of a state professional-standards board to set licensure policy.
Similar links were found between teachers’ qualifications and the proportion of a state’s education schools accredited by the National Council for Accreditation of Teacher Education.
“Poverty does matter, and spending does matter, but overall what seems to have the strongest influence is the general quality of teaching in a state,” she said last week in an interview.
But the research has failed to convince at least some of those who have questioned the value of state licensure rules.
No ‘Slam-Dunk’
The gains made by certain states could be due to changes in graduation requirements, preschool attendance, or a host of factors that the study did not examine, said Chester E. Finn Jr., the president of the Washington-based Thomas B. Fordham Foundation. Having argued that subject-matter knowledge is far more important than knowledge of pedagogy, the foundation has been highly critical of the national commission’s suggestion that a background in both areas is necessary.
“I think this is a time for humility about what we know about teachers,” Mr. Finn said. “We ought to encourage a kind of plurality of experiments and monitor how they’re working. Nobody’s formula is a slam-dunk yet.”
Although calling Ms. Darling-Hammond’s findings “provocative,” Mr. Knapp agreed that her research does not settle the issue of which state policies produce the most effective teachers.
“The analysis is, of course, at a very aggregate and, therefore, crude level,” he said. “This is not the kind of analysis that one ever stops and says, ‘Now I know everything there is to know about these relationships.’ It’s what we’d call a very early warm-up to things we hope to do in the coming years.”
