Factorial designs are widely used for studying multiple treatments in one experiment. While "long" model t-tests provide valid inferences, "short" model t-tests (ignoring interactions) yield higher power if interactions are zero, but incorrect inferences otherwise. Of 27 factorial experiments...

We use a panel survey of ∼19,000 primary-school-aged children in rural Tamil Nadu to study 'learning loss' after COVID-19-induced school closures, and the pace of recovery after schools reopened. Students tested in December 2021 (18 months after school closures) displayed learning deficits of...

Factorial designs are widely used for studying multiple treatments in one experiment. While "long" model t-tests provide valid inferences, "short" model t-tests (ignoring interactions) yield higher power if interactions are zero, but incorrect inferences otherwise. Of 27 factorial experiments...