Researchers have tried for years to identify the characteristics of effective teachers. They have looked at test scores: do smarter people make better teachers? They have looked at credentials: are teachers with master's degrees or teaching certificates more effective in the classroom? They have looked at knowledge: are teachers who majored in the subject they teach better at teaching that subject? And they have looked at experience: are experienced teachers better than inexperienced ones? The surprising result of all this research is how little it has revealed about what makes a good teacher.
Credentials don't seem to be the answer. Master's degrees and teacher certification have no significant impact on how effective teachers are. Experienced teachers tend to be better than inexperienced ones, but there are plenty of experienced teachers who are not effective. Teachers who majored in their subject area appear to be no more effective than those who didn't, with the exception of math teachers at the high school level. And teachers who score high on tests of cognitive ability appear to be more effective than teachers with lower scores, but the research on this is spotty and not completely clear.
"People have spent the last four decades trying to uncover what it is about teachers that's important," says Eric Hanushek, one of the leading researchers in the field of teacher quality. "There are a few hints here and there, but for the most part the answer has been, we just don't know."
Researchers spent so much time trying to identify the characteristics that might predict who will be a good teacher because of how the teaching profession is structured. In most school districts, teachers are eligible for tenure after just a few years. Most schools don't do a good job evaluating teachers. Teachers who can hang on for the first few years are routinely given tenure. Then it's very difficult for schools to fire them.
"[This] makes us feel like we have to be right on the front end every time we make a decision to make someone a teacher," says Tim Daly, president of the New Teacher Project, an organization that is trying to change the way teachers are hired — and fired.
Daly and other experts say the best way to determine who will be good teachers is to get them in the classroom for a few years, observe them teaching, and measure how much their students learn.
Researchers are now focusing on what good teachers do that leads to student learning. (For some interesting perspectives on what good teachers do, check out teachingasleadership.org and uncommonschools.org.)