What is the definition of disability? There are over 40 different definitions of disability in United States federal law but NIDRR is guided by the definition of disability in the ADA. The ADA definition sets out the following criteria:
a physical or mental impairment that substantially limits one or more of the major life activities
a record of such an impairment
being regarded as having such an impairment.
The definition lends itself to activity measures and therefore to measures of political activity.