We report results from a large-scale, pre-registered randomized field experiment in 159 Norwegian schools over four years. The intervention includes students aged 7-9 and consists of pulling students from their regular mathematics classes into small, homogenous groups for mathematics instruction...

We report results from a large-scale, pre-registered randomized field experiment in 159 Norwegian schools over four years. The intervention includes students aged 7-9 and consists of pulling students from their regular mathematics classes into small, homogenous groups for mathematics instruction...