Mark Bradford, president of the school board, generated some tension when he discussed the district’s plans for standards-based grading at the sixth-grade level. And teachers who may not like it, he suggested, essentially would have a choice to make — just as people decide where they want to live, or where they might choose to work. “Once the decision is made on how we’re going to do grading in this school district," he said, “then that’s the way it’s going to be.” Kim Beeler, a parent from Southwest who has been critical of standards-based grading in middle school, quickly stood...