More than a decade of research on teacher characteristics shows that, on almost every quality measure you can think of, schools with large populations of low-income, minority, and low-achieving students get shortchanged. They have fewer experienced teachers, fewer teachers teaching within their field, and teachers who show greater variations in effectiveness, including more of the worst performers.
A new paper indicates that these patterns may be more entrenched than we knew: Even within schools, this kind of "systematic matching" of teachers to students appears to occur, likely the product of both principal and teacher decisions.
Published this month in the Sociology of Education, the paper, by Stanford University researchers Demetra Kalogrides and Susanna Loeb, and Tara Béteille at the World Bank in Washington, finds that within schools, less experienced and minority teachers are more frequently assigned classes with lower-achieving students than their more experienced or white colleagues.
That pattern could have negative effects, because prior research indicates that assigning novices to lower-achieving students can exacerbate teacher turnover. It's also likely to compound achievement gaps within schools given that, while experience isn't a great proxy for performance, teachers with three or more years of experience do better on average than those in their first year.
The researchers looked at a set of data on teacher assignments from the Miami-Dade County, Fla., school district from the 2003-04 to the 2010-11 school years, linked to the students and courses taught by those teachers. They also drew on a survey of some 6,800 teachers in the district. Only a few prior studies have probed this question before, and the current paper looks at more teacher and student characteristics, grades, and years.
Among the findings:
- Teachers with 10 to 20 years of experience had students with average prior achievement that was .10 to .20 standard deviations higher, relative to students assigned to first-year teachers, at both the elementary and secondary levels.
- Teachers who graduated from more-competitive colleges also tended to be assigned to higher-achieving students.
- Experienced teachers tended to receive "better" assignments, especially when they were in schools with a higher proportion of more-experienced colleagues.
- Black teachers generally had the most challenging assignments, particularly when they taught in schools with more white colleagues.
It isn't entirely clear what's behind these patterns, though the paper explores several possibilities. The researchers suggest that, for the third finding above, the norms of schools can shape assignments: Senior teachers seem to build up a political capital of sorts allowing them access to higher-achieving classes. Some minority teachers want to work with minority or low-achieving students, while others are probably assigned, possibly on the belief that they can establish better relationships with such students.
There's also the troubling possibility that principals are rewarding or punishing teachers through their choice of assignments and even that some kind of bias may be at work.
"Overall, the patterns of teacher assignment we observe likely result from a complex process whereby school leaders attempt to respond to teacher, parent, and organizational preferences," the researchers conclude.