The fact that 90% of the gap between high-SES students and low-SES students is attributable to home factors doesn't tell us what percent of their total knowledge students gain at school verse at home.
Sorry, I guess I misunderstood you then. I asked "what % of test score variance is caused by the home environment", and you said "80-90%". So is it fair to say that we really don't know what factors predict student achievement, all we really have is a possible explanation of one particular delta?
In that case, the story we are discussing is perhaps more useful than you initially thought.
Also, when I said the poor have gotten poorer, what I meant was that the gap between the rich and poor has gotten larger, because again that's what this study is about.
This is also unclear. In terms of dollars, sure, but not necessarily in terms of living conditions. In 1970, the rich had servants while the poor had outhouses. In 2010, the rich have iPhones while the poor have Droids (sometimes even a dumb phone without data).
Sorry, I guess I misunderstood you then. I asked "what % of test score variance is caused by the home environment", and you said "80-90%". So is it fair to say that we really don't know what factors predict student achievement, all we really have is a possible explanation of one particular delta?
In that case, the story we are discussing is perhaps more useful than you initially thought.
Also, when I said the poor have gotten poorer, what I meant was that the gap between the rich and poor has gotten larger, because again that's what this study is about.
This is also unclear. In terms of dollars, sure, but not necessarily in terms of living conditions. In 1970, the rich had servants while the poor had outhouses. In 2010, the rich have iPhones while the poor have Droids (sometimes even a dumb phone without data).