Skip Navigation

National Center for Special Education Research

Secondary School Experiences and Academic Performance of Students With Mental Retardation
NCSER 2009-3020
July 2009


Since the passage of the Education for All Handicapped Children Act (P.L. 94–142) in 1975, children with mental retardation have had increasing educational opportunities (Williamson et al. 2006). In more recent years, the move toward greater inclusion of students with mental retardation has fueled interest in the academic and social outcomes for these students, as researchers, educators, and advocates consider the implications of educating students with mental retardation in general versus special education settings (Freeman and Alkin 2000; Hughes et al. 2002; Lipsky and Gartner 1997; Sandler 1999). In addition, concerns have been raised as to whether curricula and instruction provided in various instructional settings are effective, appropriate, and properly implemented (Bouck 2004; Conderman and Katsiyannis 2002).

To address these issues and support successful outcomes for students with mental retardation, it is important to understand their educational environment. For instance, what courses are students with mental retardation taking and in which instructional settings? What are the characteristics of classroom instruction, and what types of accommodations are provided? Do students with mental retardation actively participate in their classes, and how does this participation vary by instructional setting? Ultimately, what are the academic outcomes of students with mental retardation?

The purpose of this fact sheet is to explore the secondary school experiences of students with mental retardation. Topics include the instructional practices in general, vocational, and nonvocational special education classrooms; the participation of students in various classroom settings; accommodations and support services provided to students; how their experiences compare with those of their classmates; and how students with mental retardation perform academically.

Findings are based on data collected from school staff during Wave 1 of the National Longitudinal Transition Study-2 (NLTS2)1 and from direct assessments of the academic achievement of youth with mental retardation. Mail surveys were conducted with staff in the schools attended by NLTS2 sample members in the spring of the 2001–02 school year; students were 14 through 18 years old at the time.2 School staff who were knowledgeable about the students' overall school programs and about their special and vocational education courses were surveyed.3 For NLTS2 sample members who were reported by school staff to be enrolled in at least one general education academic class, teachers of the first such class in each student's school week were surveyed.4

In addition, direct assessments of youths' academic achievements were conducted in 2002 and 2004, when youth were 16 through 18 years old, using six subtests from the research edition of the Woodcock-Johnson III Tests of Achievement (WJ III) (Woodcock, McGrew, and Mather 2001).

If the direct assessment was reported to be inappropriate because youths' disabilities made them unable to follow instructions or answer questions reliably, an adult-reported functional assessment was completed to measure adaptive and problem behaviors related to functional independence and adaptive functioning in school, home, employment, and community settings.

These data offer a national perspective on the secondary school experiences of students with mental retardation who received special education services from or through their school districts when they were sampled in 2000. Students in the NLTS2 sample upon whom this fact sheet is based were identified by their school districts as having mental retardation as a primary disability.5 States classified students as having mental retardation in accordance with federal regulations for the implementation of the Individuals With Disabilities Education Act Amendments of 1997 (P.L. 105–17) (Knoblauch and Sorenson 1998). However, states differed in the specific criteria they used for identifying students with mental retardation. Moreover, most states did not distinguish degrees of severity of mental retardation, resulting in a category with a wide range of functional levels.

One measure of the degree of severity of mental retardation available to NLTS2 is a parent-reported rating of the child's ability on four functional cognitive skills—reading common signs (e.g., exit, danger), telling time on an analog clock, counting change, and looking up phone numbers and using the phone.6 For the students with mental retardation, a summative scale of these ratings ranged from 4 (all skills done "not at all well") to 16 (all skills done "very well"). Twenty percent of students with mental retardation scored in the high range (15 or 16), 57 percent in the moderate range (9 to 14), and 23 percent in the low range (4 to 8). These findings suggest that students with mental retardation represented in NLTS2 ranged from mild to severe in degree of mental retardation.


1 The National Longitudinal Transition Study-2 (NLTS2), being conducted by SRI International for the U.S. Department of Education, has a nationally representative sample of more than 11,000 students who were in at least seventh grade and receiving special education services in the 200001 school year. NLTS2 students were chosen from rosters of students receiving special education from or through public school districts. Districts were instructed to include all students for whom they were responsible, regardless of where they went to school or the type of school attended (e.g., a residential school in another state). Approximately 1,000 youth with mental retardation are included in the sample. This sample is designed to represent a total of 1,838,848 youth with disabilities and 213,552 youth with mental retardation, according to federal child count figures (U.S. Department of Education 2002). See for more information about the study.

2 Much of the information presented in this fact sheet also is included in Wagner, Newman, et al. (2003); Levine, Marder, and Wagner (2004); and Wagner et al. (2006).

3 This survey is referred to in this fact sheet as the student's school program survey.

4 This survey is referred to in this fact sheet as the general education teacher survey.

5 Studies conducted by Gresham and colleagues (1995), which investigated the accuracy of school district evaluations of students with disabilities, revealed that schools often served students under inappropriate disability labels. Therefore, the identification of mental retardation on the basis of staff-reported data should be interpreted with caution due to the potential limitations involved in this method of data collection.

6 See Wagner, Marder, et al. (2003) for the full report.