raises questions about both the validity and the reliability of various disability measures currently in use in household-based surveys. Among the goals of the workshop was the identification by participants of gaps in knowledge about the error properties associated with the measurement of people with disabilities and the development of a research framework to address those gaps.
The framework outlined by the participants encompasses four broad areas of research:
Coverage Error. To address the serious shortage of research on the effects of coverage error on estimates of the population of persons with work disabilities or potential SSA applicants and beneficiaries, research is needed on the assessment and reduction of errors related to the choice of sampling frame and screening instruments.
Measurement Error. In light of the volatility evident in the limited empirical literature investigating the error properties associated with measures of disability and work disability, research is needed on the assessment and reduction of measurement error.
Nonresponse Error. To address the paucity of research on the effects of nonresponse error, research should be directed toward understanding the correlates of nonresponse and the impact of differential nonresponse on estimates of the population of persons with work disabilities or potential SSA applicants and beneficiaries.
Environment. To address the void between conceptual models of disability that identify the role of the environment in disability and the current set of measures used in surveys of persons with disabilities, research is needed on the development and assessment of effective measures of the environment.
Coverage error defines the failure to include all eligible people on the list or frame used to identify and sample the population of interest. The use of screening questions to identify the population of interest leads to an additional source of coverage error—the exclusion of persons because of inaccurate classification at the time of the screening.
Household-based data collection efforts, by definition, eliminate from the sampling frame those members of the population who are homeless, as well as those who are living in institutions. Those residing in group homes, assistedliving facilities, and other new types of living arrangements may or may not be included in the frame, depending on how the distinction between institutional