Not the score expert OR the fastest poster, !

Dr. Ruf ... thank you so much for that informative post. How does the GAI on the WISCIV factor into what you're saying? Could you replace the IQ numbers you quoted w/ GAI as long as there were no LDs causing the disparity?

Okay, a 140 on the SB5 will generally translate to at least a 165 to 170 on the SBLM (and other tests even older with a similar scale). It depends on which subtests the child is strong or weak at. High fluid reasoning and vocabulary boost your score more than other subtests on the SBLM. A 150 is extremely, extremely rare on the SB5 (or WISC-IV) and would generally translate into over 200 on the SBLM. Think of it this way, between IQs of about 85 to 115, the old test and the new tests (and this includes the school-given CogAT and OLSAT) pretty much overlap. Scores mean about the same. As you move away from the middle of 100 IQ, past the first standard deviation (85 or 115) each point means more difference in ability compared to the old SBLM. This means that the difference in ability between IQs of 95 to 105 really is about 10 points. But, the difference between IQs of 105 and 115 is much larger, more significant. Each 10 points on this scale is a larger difference in actual ability. The difference between a child with a 135 or a 145 is huge! The 135 child could finish typical elementary school in two or fewer years while the 145+ child could finish in less than half a year if given the chance. The reason is that the 145 child has a brain that was able to absorb more from his or her environment both before and after entering school -- so they already are almost done with anything that would be presented in elementary school.