Targeted to mental retardation/developmental disability (MR/DD) and vocational rehabilitation agencies, developmental disabilities councils, consumer and advocate groups, and protection and advocacy programs, this manual is designed to assist in the development of state-level data systems responsive to current accountability requirements. It also provides the basis for improved day and employment services for people with disabilities. The manual is organized around three critical issues facing MR/DD policy makers and program administrators. The first issue, data collection, focuses on critical data sets, data selection, and collection criteria, and data collection formats. The second issue, data utilization, discusses how data are used for policy development, program development, and program monitoring. The third issue, design and implementation, addresses potential solutions to barriers identified in a national MR/DD agency information system survey. The manual stresses two key themes: (1) an increasing need for accountability and responsiveness to contemporary issues in MR/DD services related to employment options, community integration and participation, choices and decision making, and transitioning to environments that are more interdependent, productive, and integrated; and (2) changing data system requirements brought about by the significant paradigm shift that is occurring in MR/DD services. (Contains 38 references.) (CR)