A study released last month by Ohio's Buckeye Institute for Public Policy Solutions reveals some not-so-surprising, yet significant, results. In The Determinants of Student Achievement in Ohio, Matthew Carr studied both traditional public school districts and public charter schools, examining a number of factors including a number of teacher measures that do or do not impact on student performance.

When it came to public schools, Carr found that teachers' qualifications matter more than how many years they have been in the classroom. In Ohio public schools, the fact that a teacher is rated as "highly qualified" by NCLB standards has a far greater impact on student achievement than the number of years they have taught or, as a multitude of other studies have also found, whether a teacher has a master's degree.

Carr's data aren't convincing everyone. "Teachers, just like other hardworking people, improve their skills over the course of their careers...parents can tell you that seasoned teachers bring tremendous value to the classroom," said Lisa Zellner, spokeswoman for the Ohio Federation of Teachers. A seasoned teacher may add zest and practical know-how to the classroom. However, based on the data, Carr concludes that "...we need teachers who know their subjects and who have proven their competency over the subject they teach more than we need teachers with higher levels of experience or higher levels of degree attainment."