When Texas lawmakers rolled out a framework for evaluating public schoolteachers more than 15 years ago, they intended to identify ways to strengthen the state’s teaching corps, The New York Times reports. But the regular result of the largely subjective evaluations since then has been: no improvement needed. Less than 3 percent of educators receive scores below the “proficient” level, and the variation in scores from year to year has been so small that state officials stopped collecting the data from school districts after the 2010-11 academic year…