I'm basing my statements about this on having administered the ITBS intended for grades 1-8 and the ITED intended for grades 9-12 *and* having actually taken all of the tests I've administered myself. As a homeschooler, I also taught students at levels K-12 in language arts/English and math from the K level through Algebra II. I have also had my kids take the MAP and the WJ-III at various times through the years.
Have you, however, given the same child both the grade level ITBS and an above level ITBS and seen if the SS is similar on the two different tests? That's what I'm doubting for the reasons others have probably articulated better than have I.
I'm not mentioning all of this because I'm trying to impress anyone. Over the years, as a homeschooler, I've been truly interested in how my kids' achievement on standardized tests corresponds to their day-to-day achievement on their schoolwork.
Don't worry about that at all. I don't take it as bragging and I don't mean to be argumentative! I'm just a skeptic and have enough testing data on my own kids as well as some testing background myself that I'm not really sure that these types of extrapolations can be made.
What I've found is that *mastering* the material at a particular level (and not knowing any more than that) seems to correspond to placing in the 90th percentile and above for that level.
I'd totally agree with this. I've tested kids on the SAT-10 before and have seen something similar.
