Table 25. Performance on functional rating scales of youth with mental retardation who could not participate in the direct academic assessment and of youth in the general population
|Percent with standard scores that were:1|
|More than 2 standard deviations below the mean||From 1 to 2 standard deviations below the mean||0 to 1 standard |
deviation below the mean
|Above the mean|
|Youth in the general population2|
|Broad independence (overall score)||2||18||30||50|
|Youth with mental retardation|
|Broad independence (overall score)||89||7||2||1|
|Social interaction and communication||90||5||4||1|
|1 Based on a mean standard score of 100 and a standard deviation of 15.|
2 Youth in the general population refers to the Woodcock-Johnson norming sample.
NOTE: Percentages are weighted population estimates based on samples that range from approximately 540 to 560 youth across variables.
SOURCE: Woodcock-Johnson, Tests of Cognitive Ability: Standard and Supplemental Batteries, Norm Tables, 1989; U.S. Department of Education, Institute of Education Sciences, National Center for Special Education Research, National Longitudinal Transition Study-2 (NLTS2), student assessments, 2002 and 2004.