I was worried that the tests being used had inappropriate ceilings for this type of analysis, but according to their data it's possible to score several years ahead in 3rd and 8th grade.
I'd be interested to see how much variation there is year to year, to see if there's a bit of a regression toward the mean type of effect going on.
I checked 2 local school districts. One is known for having great gifted education, but never allowing grade skips (I suppose the theory is that the gifted accommodations are so good that no one would need a skip.) The other allows skips. The one that never allows skips ranked higher in this assessment. It's probably not a big contributing factor, but it's one of those details that's easy to overlook in this type of analysis.
