The prospect that key constructs will force new measurement challenges over time is a common problem in social measurement. The chief model to address this problem in other fields is to form partnerships with the scientific field allied to the constructs being measured. An ongoing program of measurement development is needed, allied with the conceptual developments in the field. Such research, when conducted outside an agency but guided by the mission of the agency, can supply the agency with proven measurement approaches when the new concepts become integrated into statutes guiding program designs. For example, small-scale studies examining how environmental impacts on disability self-reports manifest themselves can be valuable to the development of structured survey questions. The Disability Research Institute is one possible locus for such research.
Because notions of disability and models of influences on disability are constantly changing, any ongoing monitoring system to monitor the phenomena must adapt and change over time. This can be accomplished only with ongoing investment in new methods of measurement.
In order to develop a monitoring system in collaboration with other relevant agencies, the following elements are necessary:
SSA should set aside a multiyear planning period to systematically design and establish the proposed disability monitoring system;
the system should be designed with sufficient flexibility to accommodate the evolving medical, legal, social, and policy perspectives of disability;
the system should use as much as possible the design and data from existing federal surveys that measure disability in the population (e.g., NHIS, NHANES, the American Community Survey), by further cultivating partnerships with the agencies that conduct these surveys; and
SSA should ensure the availability of sufficient qualified research staff to design and oversee the proposed disability monitoring system.
While data gathering and analysis of the NSHA are under way, the committee encourages SSA to begin planning a national disability monitoring system to serve as its main information source for program planning and assessment. The general goal of the monitoring system would be to continuously monitor the number of Americans who are eligible to receive SSA disability benefits (i.e., the size and characteristics of the popu-