Computer modeling with crowd-sourced case data shows large outbreaks of COVID-19 in schools are not common, and suggests the best approaches to reducing transmission are masking and smaller class sizes. — During the COVID-19 pandemic, public health officials promoted social distancing as a way to reduce SARS-CoV-2 transmission. The goal of social distancing is to reduce the number, proximity, and duration of face-to-face interactions between people. To achieve this, people shifted many activities online or canceled events outright. …