As with many applied research programs, the assessment of SSA's decision process involves a phenomenon that is affected by changes in the external environment. For example, as the universe of jobs changes, the set of functional requirements one needs to be qualified for any job would also change. As the economy changes or as physical and mental impairments recognized as debilitating evolve, the set of functions to measure might also change. As researchers invent medical and social measurement techniques, the set of functions that are feasible to measure changes. For all these reasons, SSA should not view the current research activities as discovering permanent solutions to the problems it faces. Research to evaluate decision processes should be an ongoing program. This could be integrated into a system designed to monitor the size of the pool of persons with disabilities.

In addition, SSA's current plans generate the need to consider a longitudinal program of evaluation. The functional measurement to be used in DES will be based on measures newly developed by the integration contractor. Analysis of the DES may show that the set of functional assessments is not adequate for use in a decision process. Alternatively, other SSA research may demonstrate that new measures would offer potential improvements over the set used in the DES.

Missing from all the contract activities completed and underway is any effort to stimulate exploration of alternatives to the traditional approaches. SSA should devote more attention to testing and experimentation. It should consider awarding a series of small grants or contracts to bring together experts and consumers to brainstorm innovative approaches. SSA will need tools to evaluate the performance of the new candidate measures relative to those used in DES. The committee believes that SSA should identify ways to test new ideas in future studies, including randomized controlled experiments of alternative procedures, which would facilitate ongoing improvements in SSA's disability decision process.