I posted here for the first time not too long ago with similar concerns, and after Dottie and others offered their help and experiences I felt better about other factors (achievement tests, child's accomplishments, teacher observations, etc.) actually guiding my son's educational experience... however, I thought you might be interested in reading some of the articles I originally found on the SB 5 and how it can score certain children lower. If you're like me you might've already googled the heck out of it as soon as you got the score and have already seen these, but maybe there is something of interest for you in them!
http://www.thefreelibrary.com/Gifted+and+highly+gifted+students:+how+do+they+score+on+the+SB5%3F-a0150850213
http://www.hoagiesgifted.org/highly_profoundly.htm http://www.assess.nelson.com/pdf/sb5-asb3.pdf http://books.google.com/books?id=Hb...CC4Q6AEwCDgK#v=onepage&q&f=falsehttp://www.gifteddevelopment.com/PDF_files/testing.pdf http://www.gifteddevelopment.com/PDF_files/assess.pdfSorry there are so many -- I know some of them are really long and wordy, but if you scroll down sometimes you'll find comparison tables on them. Hope you find some of them helpful.
