Well, I can't answer your question, but I can say that the most useful tests in terms of finding out where my kid is compared to his classmates and where he should be going next have been the NWEA MAP tests. The schools that use these best will group kids with similar scores together and provide appropriate content based on what the students already know. And though of course we're talking GT, these tests are useful to educating of all kids, GT or not. Avoids the whole issue of GT - teach the the readiness of the kid. (Yes, of course this is an oversimplified response.)
Yes, I see the value in tests like MAP. Our district will begin using it and, while I'm reserving a smidge of judgement until I see it in action, I tend to think it's a good move. Conceptually, I prefer adaptive testing formats like MAP that don't require students to spend a lot of time answering questions that are significantly off-level.
I guess what I'm looking for (and this is where I worry about test prep) are ways to pick out some of those "caged cheetahs". I love the Stephanie Tolan essay, "Is It A Cheetah", because it acknowledges that there are highly gifted students who are invisible in school because they never have the chance to show what they can truly do. Those students sit unidentified (even sometimes with aware, advocating parents) because their classroom performance looks unremarkable. They will not excel on tests like MAP because they have never seen some of the content--their unremarkable classroom performance doesn't suggest a need to accelerate them to what they could do in the right circumstances.
A personal example: when DD was 9 she took a math reasoning test. She was then assessed with some district assessments, based on district standards. I did not find out until much later that she scored above the 99th percentile on both the regular and gifted scales of the reasoning test. What I was told at the time is that she was hitting standards a year or two ahead, and therefore could be instructed in the regular classroom with some differentiation. In hindsight (and with the belated information from the reasoning test), I draw a different conclusion. I conclude that the discrepancy showed inadequate classroom instruction. It was improperly paced given what she was capable of acquiring.
For students who need something other than the opportunity to work with materials from later grades (or even in those higher grade level classrooms)--for students who actually need instruction delivered in a different manner and at a different pace, acheivement tests will continue to be an inadequate identification tool. Acheivement tests will particularly miss the gifted children who come from uneducated family backgrounds or who have had undifferentiated classroom instruction and opportunities. In many ways, I think these are the children who most need to be identified early on, and who most need intervention that is based on ability rather than acheivement.
Which brings me back again to my discomfort with test prep for reasoning tests. How do we find those kids if they have peers who are able to prep for these tests when they are not able to do the same? Am I just not showing enough confidence in the quality of the tool? Does prep not make a significant enough impact to worry about?
