A friend of mine was complaining to me the other day about her son’s teacher. She spoke about how much further behind her son’s class was compared to the other classes in the same grade, and wondered what impact that would have on her son.

Unfortunately, she has no idea whether her son’s teacher is actually ineffective or if it was just her perception. More importantly, neither does the principal or the teacher.

That’s because in my friend’s district, as with most districts nationwide, teachers are not evaluated on how they impact their students’ achievement. As the report the Center released today, Building a Better Evaluation System, found, it is more than likely this teacher received a “satisfactory” rating on his or her most recent evaluation. That’s the rating the vast majority of our teachers receive. As a matter of fact, less than 1 percent of teachers nationwide are rated “unsatisfactory.”

I don’t mean to bash this or any other teacher. As with any profession, there are people that are very good at their jobs, and those who are not. It’s just that most teacher evaluations currently aren’t very good at identifying which are which.

Because current teacher evaluation systems are lacking, there has been a push by the Obama Administration and some national foundations to revamp the way teachers are evaluated by measuring teacher effectiveness on how much a teacher contributed to their students’ achievement over the course of the school year. Sounds simple enough. Most of us are evaluated in much the same way, so why shouldn’t teachers? Well, evaluating teachers isn’t so easy — but it can be done, as our new report points out.

To learn more about how to include measures of student achievement in evaluating teachers, check out the Center’s latest report, Building a Better Evaluation System. –Jim Hull