On this morning’s commute, I caught up on a new NBER Working Paper: “Education Quality and Teaching Practices,” by Marina Bassi, Costas Meghir, and Ana Reynoso.
Here is the abstract: “This paper uses a RCT to estimate the effectiveness of guided instruction methods as implemented in under-performing schools in Chile. The intervention improved performance substantially for the first cohort of students, but not the second. The effect is mainly accounted for by children from relatively higher income backgrounds. Based on the CLASS instrument we document that quality of teacher-student interactions is positively correlated with the performance of low income students; however, the intervention did not affect these interactions. Guided instruction can improve outcomes, but it is a challenge to sustain the impacts and to reach the most deprived children.”
Why no effect for lower-income students? To expand a bit on the abstract: “The most striking result from the table is the association between better student teacher interactions (reflected in a higher CLASS score) and the performance of low income students. In effect, one additional standard deviation in the principal component of CLASS scores is associated with a higher SIMCE test score for low income students of between 15% and 20% of sd units. These results are robust to adjustments in p-values to control for the FWE rate. For higher income students, effects are smaller and in some cases insignificant.”
So if the quality of interactions is particularly important for lower-income students, and the intervention isn’t affecting those interactions, then that could explain the differential effects. It’s an interesting hypothesis, and it points to the ongoing need to better understand what’s happening in the classroom.
Here’s a little more on the intervention: “The main intervention of the program was to support teachers through a modifed method of instruction by adopting a more prescriptive model. Teachers in treated schools received detailed classroom guides and scripted material to follow in their lectures.”