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MarcTheEngineer comments on Self-fulfilling correlations - Less Wrong

103 Post author: PhilGoetz 26 August 2010 09:07PM

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Comment author: MarcTheEngineer 27 August 2010 09:38:30PM 2 points [-]

I was thinking of that exact example with regards to the posts discussion on hypothetical Montessori schools.

The filtering effect still wouldn't vanish - instead of filtering FOR the most engaged parents it would filter AGAINST the least engaged (I.E. all the parents that cared would put their kids into Montessori, the parents who didn't care would just put their kids into whatever school was the most convenient for them)

Comment author: Viliam_Bur 13 February 2012 04:44:48PM *  2 points [-]

You are right. Unfortunately, "any parent who cared at all" is still a significant selection.

Also there are different kinds of "care". For example a parent may spend their time choosing the right school, and even pay more money for the school... and yet completely ignore what their children are doing at the school. The filter of Montessori schools may work on both these levels -- require both selection and later parent participation. I am not familiar with details of Montessori schools.

A data point: I taught at a school where student grades were not written on paper, but only on a school website. Parents received a password they could use to see their child's grades. During the year 1/3 passwords were never used. That means that parents of 1/3 children either did not care what grades their child has or at least did not care to verify what their child reported. It was a school that required special tests for a child to be accepted, and for many children it was inconveniently far from their home -- so parents did care about choosing the right school, but then 1/3 of them stopped caring about what happened in the school.

I guess this could be explained by signalling. Choosing your child's school is a one-time activity that signals that you are a great parent. Reading your child's grades online is invisible (unless someone curious looks into logs later), therefore useless for signalling.