Scrolling

• Does the window use either the standard scroll bar mechanism or the hand for scrolling? If it uses the hand, does the pointer either always become a hand in the window or appear highlighted in a tool palette?
• Does clicking a scroll arrow cause the document to move a distance of one unit in the chosen direction? (The unit should be appropriate and meaningful for the application.)
• Does clicking in the scroll bar below the scroll box advance the document by a windowful? (A windowful is the height or width of a window, minus a one-unit overlap.) Does clicking above the scroll box move the document back by a windowful?
• If the user drags the scroll box and then moves the pointer well outside the scroll bar, does the scroll box snap back to its original position?
• Is the function of the arrow keys different from the function of the scroll bar? (Arrow keys should not substitute for scroll arrows.)
• Are the scroll bars inactive when the document is no larger than
  the window?
• Are the scrolling keys on the keyboard (Page Up, Page Down, Home, End) supported? Note that these keys do not move the insertion point and do not affect the selection.
• Does the scroll box indicate the approximate position of the visible part of the document in comparison to the whole document?