individual. As such, the framework differs from theoretical models that depict disability as a process beginning with impairment and ending with social role or behavioral restrictions or models that focus on disability as merely a functional limitation, that is, the restriction in physical functional activity and task activity associated with the impairment (Altman, 2001). In addition, the use of neutral terminology (as opposed to negative terminology such as handicap or disability) is emphasized in the ICF framework.
The ICF focuses on nine domains: (1) learning and applying knowledge, (2) general tasks and demands, (3) communication, (4) mobility, (5) self-care, (6) domestic life, (7) interpersonal interactions and relations, (8) major life areas, and (9) community, social, and civic life. Within these nine domains, body function or capacity independent of environment as well as performance (which is dependent on environment) are to be measured. For example, an individual may have a latent allergy (body function) that manifests itself only when the person is exposed to the allergy agent, which may or may not therefore affect performance. Performance includes both execution of actions by an individual (activity) and involvement in life situations such as work (participation).
The release of the ICF in the spring of 2001 has resulted in a number of research activities related to the design of questionnaires that can be mapped to the ICF framework. Much of this research focuses on question wording to measure activity (and the use of assistance in the performance of activities) and participation (both extent of participation and satisfaction with participation). There is a great deal of research interest related to the development of a single reliable and valid question that could be proffered for use in censuses internationally. In addition, questionnaire design research has focused on the construction of both short- and long-form questionnaires with known measurement error properties. The movement from dichotomous response options to continuous response classification has led to questions as to the impact of cutpoint decisions on estimates of the “disabled” population as well as their impact on the distribution of the characteristics of the population.
A key component of good fiscal management for the Social Security Administration is having sufficient information to understand and predict growth in the pool of persons eligible for disability benefits as well as understand the factors that impact the application process, including motivation to apply for benefits. Medical models of disability have historically been insufficient to explain unexpected growth in the size of the