NCEO Brief

January 2012
Number 5

A New Series of Briefs for the Race to the Top (RTTT) Assessment Consortia

Performance of Special Education Students:
Implications for Common State Assessments

The performance of special education students on state assessments has been the subject of much discussion and concern. A common belief is that all special education students perform poorly on state assessments.

There are many misperceptions about the performance of students with disabilities. It is important for the Race-to-the-Top Assessment Consortia to recognize these misperceptions and their implications for common assessments.

This Brief presents information on the range in performance of special education students. It also highlights the changes in the performance of this subgroup over time.

Performance Levels and Ranges

Historically, special education students, on average, have performed below students without disabilities. Yet there is diversity in the percentages of special education students performing at the proficient and above levels among the Consortia states (see Figure 1).

In both the SMARTER Balanced Assessment Consortium (SBAC) and the Partnership for Assessment of Readiness for College and Careers (PARCC) Consortium, the percentage of special education students scoring proficient and above varied from about 15% to more than 70% across states.

Across all states within and outside of the consortia, there are clear gaps between the performance of non-special education students and special education students. Nevertheless, the extent of the gap varies by state. Different levels of performance for special education students are evident even in states that have similar percentages of non-special education students who are proficient and above (see Figure 2).

The percentage of students who scored at a proficient or above level hides the range of performance levels of special education students. Students earn scores that may be near to the proficient cut or far from it. Figure 3 shows the ranges in the performance of special education students in one state, based on a more fine-grained look at scores (i.e., deciles; students’ scores are divided into ten groups of equal frequency. In this Brief, Decile 1 represents the highest 10% percent of the scores). Notable is the fact that special education students perform at all performance levels, from the highest to the lowest. Also notable is that although the largest proportion of special education students is in the lower performance decile, most of the students in the lowest decile are students who are not in special education. Similar distribution patterns have been previously highlighted in other analyses (Marion, Gong, and Simpson (2006) described the overlap in performance levels for special education students and non-special education students in another state)  as well as in data from other states (we examined ranges in three other states as well as the state represented in Figure 2; all of the states showed similar overlap in the range of performance of special education and non-special education students).

Figure 1. Rates of Special Education Students Proficient and Above on Grade 4 Reading Assessments

Figure 1 Chart

Source: 2008-09 assessment data for grade 4 state reading assessments submitted to the U.S. Department of Education. Rates of students proficient are based on the number of students tested. The state membership in the Consortia reflected in this figure was accurate as of December, 2011. 

Figure 2. Percentage of Students Proficient on Elementary (Grade 4) Reading Assessments in 2008-09

Figure 2 Chart

Legend: Heavy Solid Bar = Special education students’ percent proficient. Diamond = Non-special education students. Line = Gap between special education students and non-special education students. For some states the non-special education students comparison group may be all students, including those in special education.
Source: NCEO Technical Report 59 (see Resources).

Figure 3. Percentage of Special Education and General Education Students in Each Decile on a Test in One State (Grade 4, Reading)

Figure 3 Chart

Source: Anonymous state’s data for special education and non-special education students on the grade 4 reading assessment.

Increasing Performance Over Time

The performance of special education students is often thought to be persistently low. Yet state assessment data, as shown in Figure 4, indicate that the performance of the special education subgroup is increasing over time. Increases are greater for students in elementary school compared to middle school, and greater for students in middle school compared to high school.

Figure 4. Average Changes in Performance of Special Education Students Over Time

Figure 4 Bar Chart

Source: Annual Performance Report data submitted to the U.S. Department of Education for grade 4, 8, and high school reading assessments in 2002-03 and 2006-07.

Note: The change across years was calculated for each of the states that had data for 2002-03 and 2006-07 in grades 4, 8, and high school. The average change was calculated for those states.

Concluding Thoughts

Wide variation exists across states within each Consortia in the percentage of special education students who are proficient or above on their state assessments. Although the Consortia will be developing their own assessment systems, and in doing so will set their own performance criteria, it will be important for them to know where the states in their Consortia are coming from in terms of the performance of their students. This includes having awareness of the performance levels of special education students.

Although many special education students are low performing, they are not the only low performing students and are generally not the most prevalent low performing students. It is important not to forget that there are some very high performing special education students. Further, special education students, on average and in most states, have shown increased levels of performance since 2002-03. The Consortia and states within them should look at their own data on the performance of special education students, address whether changes in their own content or achievement standards may have affected change, and think through their own transition needs as they move to the new assessments and the new performance standards.


Meeting the Needs of Special Education Students: Recommendations for the Race-to-the-Top Consortia and States. (2011). Thurlow, M. L., Quenemoen, R. F., & Lazarus, S. S. Washington, DC: Arabella.

Mining Achievement Data to Guide Policies and Practices on Assessment Options (Teleconference). Marion, S., Gong, B., Simpson, M.A. (2006). Minneapolis: National Center on Educational Outcomes. Available at:

2008-09 Publicly Reported Assessment Results for Students with Disabilities and ELLs with Disabilities (Technical Report 59). Thurlow, M. L., Bremer, C., & Albus, D. (2011). Minneapolis, MN: University of Minnesota, National Center on Educational Outcomes.


Ideas that Work logoNCEO Brief #5

January 2012

This Brief reflects many years of work by all NCEO staff. Contributors to the writing of this Brief were, listed alphabetically, Kamarrie Davis, Sheryl Lazarus, and Martha Thurlow.

NCEO Co-Principal Investigators are Martha Thurlow, Sheryl Lazarus, and Rachel Quenemoen.

All rights reserved. Any or all portions of this document may be reproduced and distributed without prior permission, provided the source is cited as:

NCEO. (2011, January). Performance of special education students: Implications for common state assessments (NCEO Brief #5). Minneapolis, MN: University of Minnesota, National Center on Educational Outcomes.

NCEO Brief is published by the National Center on Educational Outcomes. The Center is supported through a Cooperative Agreement (#H326G050007) with the Research to Practice Division, Office of Special Education Programs, U.S. Department of Education. Opinions expressed herein do not necessarily reflect those of the U.S. Department of Education or Offices within it.

This document is available in alternative formats upon request.

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