Main Results
Before the intervention
Large gender gap in math before the intervention in favour of boys (0.21 standard deviation)
larger than the national average at the same age
in line with INVALSI results for the same classes (0.24 s.d)
Checks
Balance
Children characteristics: pre-test score, special education needs and disability, gender
Family backgorund: parental education, migratory background
Teacher's c characteristics: education, experience, type of contract
Class characteristics: average pre-test score and variability in the classclass size
Differences between the treatment and the control groups are small and mostly not statistically significant
Compliance
All classes in the treatment group were exposed to the intervention
All classes in the control group were not exposed to the intervention
Large majority of the children actually attended the majority of the lab sessions (98.6% attended at least 3 out of 5 sessions)
Attrition
About 5 percent of children not present at the post-test
No difference treated/controls and boys/girls
About 15 percent of children not present at pre- or post-test
Pre-test during flu peak
Significant difference treated/controls
Balance after attrition is confirmed
No impact on results
Results
Core results
Large and significant improvement of girls' math skills (+0.14 s.d.)
Large and policy-relevant
Zero effect for boys
Reduction of the GGM by more than 40 percent
By prior math skills
No effect for boys, irrespective of their starting level
Large effect for girls, increasing with prior achievement