CTY is grade-leveled, rather than being age leveled, which might have an impact. A homeschooled kid can be working far above typical-for-age grade level, but still be appropriately classified in an age-appropriate grade. Whereas a publicly-schooled kid might have to skip grades in order to get the same material.
I think this is true. I actually think kids should be compared by age or DOB rather than by grade, which becomes meaningless for these HG+ kids. I'm still calling my homeschooled kid a 4th grader. My output and work hours expectations are at that 4th grade level. The input is at his working level - algebra for math, jr. high for LA, all over the board for what he chooses reads, etc.
There are certainly homeschoolers that make this kind of testing a priority and take a lot of time prepping and understanding the format. Which is totally fine. But I think those kids are clearly going to be at a huge advantage!
