What Counts as a Learning Disability
Assessing those who may have a learning disability is not an easy task. Several hundred assessment tools are currently use, and it is important to use more than one when trying to pinpoint a disability. Schools generally use one of three primary model; test performance compared to IQ, test performance compared to grade level, or a review of scatter-plot variations within a test score. What’s importance is know the local parameters for disabilities. For example, in schools in poverty-stricken area, many of the so-called disabilities are poverty related. So you should understand a student's background (literally and figuratively) before attaching labels. Using any of the following definitions, consider all students, even those with a learning disability, as gifted, whether or not they fit the appropriate definition or need services.
Determinations for Disabilities
Some schools limit the criterion solely to a discrepancy of 1 or more standard deviations (approximately 15+ points on a bell curve with 100 as the mean or 3+ points on a curve with 70 as the mean) between achievement scores and "intellectual potential" as measured by standardized tests. For example, setting aside whatever you may think of IQ tests, suppose you have a student with a verbal IQ of 100, who is thus considered to be of average intellectual potential. If that student is unable to earn a standard score of more than 70 on standardized test (e.g., reading comprehension. vocabulary, writing) and is 2 standard deviations below the mean, that student is likely to be considered learning disabled.
In other localities, there must be a difference of two or more grade levels between potential and actual performance also as measured by standardized tests. The same student with a verbal IQ of 100 would be expected to be able to do grade-level work. If that student was instead reading, writing, spelling. or doing math at a level two or more years below grade level. the school might deduce the presence of a learning disability.
Still other schools recognize intra-test scatter as indicative of a learning disability. For example, on a standardized test of intelligence, one would expect a student with overall delayed development or mental retardation to have scores below average in all areas. In this view, students with a learning disability may have some average scores and some below-average scores. There may be a significant discrepancy between the verbal and performance scores on an IQ test so that the full-scale IQ accurate indicator of intellectual potential at all. This is just one reason why complete testing is critical to find out the full extent of a student's capacity.