This report evaluates the degree to which current assessment practices and programs include students with disabilities. It notes the difficulty of accurately determining the participation of students with disabilities in large-scale assessment programs due to a lack of data, differing definitions of eligible testing populations, and the misalignment of data collection efforts and data management responsibilities. Specific recommendations are provided for both policymakers and local practitioners and administrators. These include identifying students with disabilities in statewide assessment programs; standardizing procedures for calculating participation rates; improving communication between state special education and assessment offices; asking good questions about state and district assessment practices; helping parents understand the importance of participating in assessment programs; and evaluating current district and state policies on participation and accommodations in assessment programs. (DB)