Schools routinely blame socio-economic factors when their charges under-perform. And too many critics nod in agreement. Not those at The Education Trust, whose new study Teaching Inequality points the finger at districts that routinely pair economically disadvantaged students with inexperienced or out-of-field teachers. Does it matter? You bet. William L. Sanders has shown that students with three consecutive years of highly effective instruction outperform peers with ineffective teachers by more than 50 percentage points--even when children began with the same score. One of the report's three case studies comes from Ohio, where the state's distribution of "highly-qualified" educators was evaluated. In our schools with the highest rates of children in poverty and minority enrollments, roughly 40 percent of teachers are not highly qualified. The rate is half that in wealthier, less racially diverse schools. In our highest-poverty high schools, almost 25 percent of math teachers are not highly qualified; that number's just 5 percent in the lowest poverty high schools. No wonder achievement gaps are so wide. Yet "highly qualified" is hardly a gold standard in this state. To be so designated in Ohio, teachers must have either a major or at least 30 hours in their teaching field, or demonstrate subject matter knowledge by passing a test. Not exactly a paragon of rigor. Worse, veteran teachers can attain the "highly qualified" status simply by filling out a checklist of past activities and professional development. With enough years in the system, large numbers of veteran teachers can be "grandfathered" into the ranks of "highly qualified" without demonstrating adequate content knowledge or competence. (Thankfully, the U.S. Department of Education has ended this option, effective the 2006-07 school year.) Compare our state to Illinois, which built a comprehensive database to examine the distribution of all the state's 140,000 teachers. The Illinois study also included indicators such as basic academic literacy, college program strength, and experience to create the Teacher Quality Index (TQI). Not surprisingly, teachers who ranked highly on the index possessed stronger academic skills--in addition to years of experience--than their lower scoring colleagues. The Education Trust report makes clear that teacher quality matters. Ohio needs a credible benchmark--similar to the TQI--to measure it. To read The Education Trust's report, click here.