Definitions from U.S. Dept of Commerce
  - From Census
  Brief, December 1997
- 
        - someone living with a disability
          
            - has difficulty performing certain functions, or
- has difficulty performing activities of daily living, or
- has difficulty with certain social roles.
 
- someone living with a severe disability
          
            - is unable to perform one or more activities, or
- uses an assistive device to get around, or
- needs assistance from another person to perform basic
              activities