Accommodations should therefore be offered for two purposes: (1) to increase the participation of students with disabilities in large-scale assessments and (2) to increase the validity of the test score information. These two objectives—obtaining valid information while still testing all students—create a sizable policy tension for the design of assessment systems, particularly when they involve high stakes.
Recommendation: More research is needed to enable students with disabilities to participate in large-scale assessments in ways that provide valid information. This goal significantly challenges current knowledge and technology about measurement and test design and the infrastructure needed to achieve broad-based participation.
In addition, students with disabilities are rarely included in adequate numbers in the pilot samples when new assessments are being developed; oversampling may be necessary to permit key statistical analyses, such as determining the impact of accommodations on test scores, norm development, and analyses of differential item functioning (Olson and Goldstein, 1997).
Recommendation: The needs of students with disabilities should be considered throughout the test development process.
As the stakes of testing become higher, there is a greater need to establish the validity of tests administered to students with disabilities. At present, policies on the kinds of testing accommodations offered and to whom they are offered vary widely from place to place (Thurlow et al., 1993). New federal regulations require that the individual education program (IEP) document the decisions made about each child's participation in assessments and the type and nature of the accommodations needed. The proportion of students that require accommodations will depend on the purpose, format, and content of the assessment.
Parents of students with disabilities play unique roles as advocates for their children's rights, important participants in the IEP process, and monitors of accountability and enforcement. If high stakes are to be attached to the assessment of students with disabilities, then parents and other members of the IEP team will need to be able to make informed choices about the nature and extent of a student's participation in the assessment and its possible implications for future education and post-school outcomes.