Some students are more apt to be assigned better or more experienced teachers than other students. That's not news. Past studies have found that lower-income and minority students tend to be assigned to teachers with less experience than their peers. 

A new study by Rebecca Wolf of SRI International plays this pattern out but goes a step further to see whether some schools or, more intriguingly, grades within schools get a larger share of novice teachers.

Wolf finds that the biggest apparent driver of differences in who gets the newest teachers within a school was the student's grade level—not whether students were high or low performing. While the level of student achievement played some role, the effect size was relatively quite small (students who scored basic on the state math test were about only one percent more likely to be taught by a new teacher than a higher-achieving student was). However, a 9^th grade student was 10 percent more likely than a 12^th grade student, regardless of her academic standing, to be taught by a novice math teacher. Sixth grade was the exception to this finding, with student achievement having a bigger impact than grade level. A low-achieving 6^th grade student (the first grade of middle school for most schools in the district) was much more likely to have a novice teacher than other 6^th grade students.

So why does assigning the newest teachers to the lowest grades in a school, especially to the lower-performing students in those grades, matter? The problem is that success in 6^th and 9^th grades, the years referred to as "transition grades," has significant implications for students' long-term educational attainment and engagement. Studies show that student experiences during these years have a relationship to drop-out and student achievement rates that can persist for years into students' academic careers.

Wolf's study may mean that principals should think twice about where they're placing their newest teachers.