Includes people with disabilities, but also many elderly users and "situationally handicapped" users. They have, e.g., problems

1. Positioning the mouse, clicking and dragging.
    Mouse operations should also be performable using the keyboard only
        (e.g., use cursor keys for navigation, function key for selecting menu items)

2. Simultaneously pressing two or more keys (e.g., CTRL and SHIFT).
     Allow users to press these keys sequentially.

3. Entering larger amounts of data
     Provide default values
          Provide next possible values when user presses a key
          Successively provide next possible value; stop when user hits a key
          Expand input to first possible value
          Allow users to define aliases and shortcuts

For severe forms of manual impairment, special input devices are needed (head mouse, foot mouse, suction tubes, speech recognition )