in trying to understand disability, trying to develop models of disability, and trying to identify measures of it. Yet this variety in approaches, language (and jargon), orientation, and focus complicates efforts at measurement and sometimes confuses interpretation of the results of the measurement.
Altman stated three objectives of her paper:
To examine the disability conceptualization transition to measurement within the general theory of disability and to compare it across areas of application
To define the sources and types of measurement that have been developed for the various theoretical concepts and examine what measures are available and how well they represent the concepts
To reintroduce the important contribution of the social and environmental context, not only to the conceptualization of disability, but also to its measurement
Altman then gave an overview of the measurement elements that are necessary to fully understand disability, reveal the strengths and weaknesses of what we have, and identify the gaps in measurement that exist.
Multiple theoretical models provide the conceptual basis for understanding the disablement process. The Nagi model (1965), developed by a sociologist, is one of the earliest and most widely known coherent organizations of the conceptual components and their relationships. It was revisited and expanded in 1991 by Nagi and also elaborated by Verbrugge and Jette (1994).
Subsequently, conceptual elements and relationships have been expanded with models from the Institute of Medicine (1991, 1997) and the International Classification of Functioning, Disability and Health (ICF) model of the World Health Organization (2001), but their elaborations do not really take new directions. They do make the components more understandable to a wider audience, provide a standardization of the language, and make things more accessible to the people who are using the models. The ICF model also provides an accompanying classification scheme that is a listing of domains for consideration when one is operationalizing a measure. It has been a very useful tool. While each of these succeeding models has made contributions, the original model is still very visible.
On the basis of these models, major conceptual elements that make up the experience of disability and need to be measured in population surveys include (the background paper and this discussion focus only on those concepts that are starred)