The stimulation intervention included weekly home visits by trained community health workers, who encouraged and instructed mothers on how to play and interact with their children. For the nutrition intervention, health workers distributed weekly nutritional supplements to homes, as well as additional cornmeal and skimmed milk powder to discourage sharing of the supplement with other family members.
Result:
Most notably, children who received stimulation achieved 0.6 more years of schooling, or 5.6 percent more schooling, than participating children who did not receive stimulation, and were nearly three times as likely to have had some college-level education.
Am I missing something in the wide gap between those figures - Children who got intervention X stayed in school for ~7 months longer and were also three times more likely to start college
The 5% more and the 300% more just seem wildly out of kilter
(It kind of makes sense - if all your peers stop school at 16 and you stay for 7 months or more, suddenly getting to college is a much easier step.) I think i am just surprised by how surprised i am
As I mention below, the very large 200% increase in college attendance is more likely to suggest that this demographic group has extremely low college attendance rates than that the intervention has an extremely high impact.
If you do your intervention and 2 out of 127 children enroll in a college when you would have expected 0.7, you've tripled the expected rate, but that was easy to do by chance.
In this case, the sample size was presumably half that, around 64.
Say...
Kids get 10.5 years schooling on average in neighborhood A. 12 years in neighborhood B. That is a 1.5 years or 15% difference. In a 12 grade system, this is the best possible result implying a 100% completion rate.
Neighborhood A sends 10% of all kids to college. Neighborhood B sends 50% of all kids to college. That's a 500% difference.
This example seems pretty plausible. A neighborhood where an average kid makes it halfway through 10th grade probably sends a lot fewer kids to college than a neighborhood with a 100% completion rate for grade 12.
Well the 5% is averaged over the whole group while the 300% is from a base rate of those who go to college.
I haven't seen the data, so I don't know if this is the case, but one explanation is that this intervention works really well for some people, and not at all for others. Also, I think "3x more likely" means 200% more people.
So the numbers could be something like: 100 participants, 5 would have gone to college. The social stimulation really benefited 10 kids. They, in turn, did years more schooling and went to college. 5% -> 15% college rate is 3x more likely, but the 10 kids' large increase in attendance was averaged out over the group of 100, so the overall increase was just 5%.
Not saying this is the case, just showing a way those numbers could be plausible.
It's really easy to see that lots of reasons that aren't directly due to the program could have caused the changes. It could have been as simple as an expectation change amongst the parents, upon joining the program; how their children will perform better and therefore they did or it could have been the parents in the neighborhood most engaged in their children having a better life and when the opportunity to join the program became available they joined.
Stuff like this is notoriously difficult to prove, but I'm hopeful and glad to see research is being done.
"The original ECD program, which lasted two years, enrolled 127 stunted children aged 9-24 months. Researchers randomly assigned these children to one of four groups: a psychosocial stimulation intervention, a nutrition intervention, both interventions, or neither intervention (the comparison group)."
That was my first thought too: the positive results could be effect of special attention and expectations (placebo effect). However comparing "both interventions" group with each single intervention group should address this.
The stimulation intervention included weekly home visits by trained community health workers, who encouraged and instructed mothers on how to play and interact with their children. For the nutrition intervention, health workers distributed weekly nutritional supplements to homes, as well as additional cornmeal and skimmed milk powder to discourage sharing of the supplement with other family members.
Result:
Most notably, children who received stimulation achieved 0.6 more years of schooling, or 5.6 percent more schooling, than participating children who did not receive stimulation, and were nearly three times as likely to have had some college-level education.