As we go At the start of the school year, schools across the country struggle with educating their students while keeping everyone safe. In some districts, children will return to full-time teaching, while others will only teach them through a screen. An estimated 20 to 30 percent of the country’s school districts – including New York City, which serves more than a million students – are planning to implement a “hybrid” model, where groups of children take turns in person on part-time schedules. U.S. governors, school chancellors, and state epidemiologists have touted this approach as the Goldilocks solution: keeping the number of children in classrooms low enough to ensure adequate social distancing while students still receive some level of basic personal learning. It seems like the perfect compromise.
However, this popular belief can be grossly wrong.
“The hybrid model is probably among the worst we could suggest if our goal is to keep the virus from entering schools,” said William Hanage, an epidemiologist at the TH Chan School of Public Health at Harvard. “I don’t see how this ultimately helps teachers,” says Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. “I don’t fully understand the hybrid model.”
Their argument is simple: if you want to limit the chances of infection for children and teachers, it is better if students spend their time in a consistent group of their peers.
In a hybrid model, a significant percentage of students are likely to mingle with other children and adults if they are kept away from school several days a week or every other week. This is especially true for younger children with working parents as the children may need to be in a daycare center to expose them to other social contacts and all of their possible infections. In the meantime, older children and teenagers will tend to hang out with their peers on their numerous “free” days. (In many districts, “distance learning” plans include only a short amount of live streaming classes per day, leaving many hours to explore other options.) The hybrid model, says Nuzzo, “only works when the students stay home alone. All this time they are out of school. “This is a strangely unrealistic assumption by policy makers.
According to Dimitri Christakis, a pediatrician and epidemiologist at the University of Washington’s School of Medicine and editor-in-chief of, all of these additional interactions are more likely to increase than decrease the risk of transmission JAMA Pediatrics. “There is a real chance a hybrid model will fuel the spread of the virus.” In his view, having 30 children in a classroom, even if there wasn’t enough space for a social distance of six feet, would be preferable to knocking out groups of half that size. In the latter scenario, each of these students would likely be exposed to more people overall. Their teachers would also be at higher risk – instead of teaching one cohort every day, they would lead two.
Martin Kulldorff, biostatistician at Harvard Medical School, sums it up as a simple question of arithmetic: “In full-time school, children are mainly in only two places and with two groups of people, at school and at home. With a hybrid model, many young children with additional people such as grandparents, uncles, neighbors, nannies or day-care workers have to be in third place. “By increasing the exposure of everyone from two locations or groups to three, the hybrid model is” the worst of both worlds “. Instead, he suggests a “hybrid teacher” model: the children stay in school all day, while the most vulnerable teachers work permanently off-campus and help their colleagues grade exams, prepare course materials or offer online tutoring for children , she has to be at home herself.
While a number of countries in Europe implemented a hybrid strategy last spring, none of the experts surveyed for this article were aware of studies on their effects on virus transmission. Aside from the potential for greater spread of infection, the educational benefits of the hybrid model can be somewhat marginal. Meira Levinson, an education expert and ethicist, told me that some students might find real value even in intermittent opportunities to learn in person – for example, through grooming frogs or occasional team building exercises. However, many others are hampered by an inconsistent schedule. She also pointed out that hybrid models do little to alleviate the childcare crisis that results from admitting children to distance learning plans.