students' disabilities ranged from speech and language impairments to mental retardation, and more than half were described as having a specific learning disability due to a psychological disorder.8
Children with disabilities vary with respect to the type and number of disabilities they have, and their disabilities vary in cause, degree, and the effect they have on the child's educational progress. Although children with disabilities are a very diverse group, data describing the demographic characteristics of students with disabilities suggest the following:
More than half of all students receiving special services are males.
Most are in elementary or middle school.
Most have no obvious disability; they have problems that are primarily academic, emotional, social, or behavioral.