December 8, 2001

UNSTABLE FOUNDATIONS OF TEACHER CERTIFICATION

American education displays a curious anomaly. Public schools demand full certification for teachers -- not that they always get it, of course, especially in specialized fields such as mathematics and science. Data indicating that schools with many poor or minority children are more likely to have uncertified teachers are cited with indignation as evidence that society is deliberately shortchanging those already most at risk.

Yet private schools typically have no such requirement, and in fact often have much lower proportions of certified teachers than the public schools with which they compete. Parents who send their children to private schools do so by choice, and often at considerable expense; they must be satisfied with the quality of education or they'll leave.

One can't say that private schools achieve superior results because their teachers avoided the initiation rite of certification. There are too many other differences between private and public school students. But it is safe to say that the lack of certification does no harm, if teachers are well qualified in other ways.

So why is certification required in public schools? Because ``everybody knows'' that certified teachers are better teachers.

How did ``everybody'' come to know that? Because all the people whose careers are built on the certification process kept saying so. Research studies proved it.

Kate Walsh, a senior policy analyst for the Abell Foundation in Baltimore reviewed those studies -- approximately 150 of them, going back almost 50 years. Her conclusion: ``The academic research attempting to link teacher certification with student achievement is astonishingly deficient'' (see ``Teacher Certification Reconsidered: Stumbling for Quality'' at abell.org on the Web).

She notes, for instance, that many researchers devise their own assessments rather than using objective measures of student achievement. Or they fail to observe the norms of statistical analysis, for instance ``failing to control for such key variables as poverty and prior student achievement.'' Or they simply misstate the conclusions of earlier researchers whose work they have apparently not even read. Walsh tells of trying to track down a paper, delivered at a 1990 conference and never published, which is frequently cited with the wrong author's name. Even the authors no longer had a copy.

Of course the education establishment is flailing away mightily at Walsh's work. Linda Darling-Hammond, professor of education at Stanford University and executive director of the National Commission on Teaching and America's future, posted a lengthy reply on the commission's Web site, nctaf.org (see under ``What's new'').

In fact, Walsh and Darling-Hammond are in agreement on two very basic principles. One is that teacher effectiveness should be evaluated based on student achievement. The other is that content knowledge is crucial.

On how to implement those principles, however, they are worlds apart. Darling-Hammond asserts that Walsh makes unsupported claims, for example, that ``verbal ability and subject matter alone are sufficient to produce effective teachers.''

But Walsh makes no such claim. What she does say is that one of the best-kept secrets about teacher quality is that statistically ``teachers with higher verbal ability produce greater achievement gains in students.''

That's not new. I once heard a talk by the sociologist James Coleman, known for his landmark research on segregation. He said he discovered in the 1960s that the single most significant factor in determining children's achievement was their teachers' performance on simple tests of spelling and vocabulary. But the result was politically unpalatable and he didn't pursue it.

Darling-Hammond's versions of other claims supposedly made by Walsh are equally fanciful. But taken together -- along with a further response by Walsh to Darling-Hammond's objections -- the papers offer a splendid overview of one of the most contentious, and significant, issues in education.

(614 words)