THis is what Hoagies tells us about the OLSAT (
http://www.hoagiesgifted.org/tests_tell_us.htm):
"The most common group intelligence tests, OLSAT and CogAT, are used in districts and programs across the country. Notable gifted professionals recommend them for screening potentially gifted children. However, a small study noted a potential problem with the OLSAT and very gifted children. While the correlation between group and individual intelligence tests is quite high for average scores, in this study that correlation almost disappeared for gifted scores. This means that while an average child will score very similarly on a group IQ test and an individual IQ test, a gifted child may not score similarly at all. And the study suggests that this group test may even result in a negative correlation for some gifted children: the more gifted the child, the lower the group ability test score! ["Investigations of the Otis-Lennon School Ability Test to Predict WISC-R Full Scale IQ for Referred Children" by Anna H. Avant and Marcia R. O'Neal, University of Alabama, Nov. 1986, ED286883] Though this study is no longer available from AskERIC, it can be obtained on microfiche from most education university libraries.
A 2001 study using the OLSAT noted a problem with the OLSAT and twice exceptional (gifted and learning disabled) students. A Comparison of the WISC-III and the Otis-Lennon School Ability Test with Students Referred for Learning Disabilities, by Thomas Guilmette et. al., Providence College and Brown University School of Medicine, showed that LD kids tended to score an average of 7.5 points lower on the OLSAT than their WISC-III full scale IQ scores. This study is available in the Journal of Psychoeducational Assessment, or for a few dollars from SAGE Publications on the 'net.
"The use of the OLSAT-6 in estimating overall intellectual abilities in children with suspected learning disabilities is not encouraged because it may frequently underestimate students' actual abilities, which may result in fewer appropriate referrals for further educational and intellectual abilities." "As with previous studies with gifted students, our research indicates that the OLSAT-6 appears to underestimate WISC-III FSIQ." -- Guilmette et. al., A Comparison of the WISC-III and the Otis-Lennon School Ability Test with Students Referred for Learning Disabilities"
My son scored much lower on the OLSAT than on the WISCIV (however, he is twice-exceptional). I believe it is timed and my understanding is that the ability to listen closely and remember oral information affects the verbal portion more significantly than the non-verbal portion of that test and that the child must be paying complete attention to each word for every verbal item in order to answer it correctly. The tester only reads the question once and the question is not permitted to be repeated.
ETA: I put very little stock on the OLSAT - I believ it misses a lot of gifted children. A LOT.
