There’s No Substitute for a Teacher, writes June Kronholz on Education Next. Students learn less when substitutes fill in.
Duke researchers Charles Clotfelter, Helen Ladd, and Jacob Vigdor found that being taught by a sub for 10 days per year has a larger effect on a child’s math scores than if he’d changed schools, and about half the size of the difference between students from well-to-do and poor families.
Columbia researchers Mariesa Herrmann and Jonah Rockoff concluded that the effect on learning of using a substitute for even a day is greater than the effect of replacing an average teacher with a terrible one—that is, a teacher in the 10th percentile for math instruction and the 20th percentile in English instruction.
Some school districts — including Maryland’s Baltimore County, Florida’s Hillsborough County, Georgia’s Cobb County, and Colorado’s Jefferson County — hire subs with only a high school diploma or a GED, writes Kronholz. Her son worked as a sub right after graduating from college.
. . . most often, teachers left behind worksheets, quizzes, and videos for him to monitor, amounting to what University of Washington professor Marguerite Roza calls “a lost day for most kids, regardless of the qualifications of the sub.” Indeed, many schools are looking for someone just to keep order rather than to teach differential equations.
“A lot of times, principals are just praying for basic safety,” said Raegen T. Miller, who has studied teacher absenteeism as associate director of education research at the Center for American Progress and as part of a Harvard University team.
Some 5.3 percent of teachers are absent on any given day, according to Education Department figures, but reporting is haphazard, writes Kronholz. Eight to 10 percent of teachers are out on any given day, according to surveys by Geoffrey Smith, who founded the Substitute Teaching Institute at Utah State.
Schools that are large, urban and/or serve low-income students rely heavily on substitutes to fill in for missing teachers. Camden, New Jersey needs subs for up to 40 percent of its teachers each day, the district told the local newspaper. Teachers in Providence, Rhode Island were absent an average of 21 days each per school year in 2011, according to a report by Brown researchers.
In well-run schools, students show up for class and teachers do too. But low-performing schools get stuck in a vicious cycle: Students cut class: frustrated teachers call in sick; substitutes hand out worksheets; students skip more classes.