gorilla arm

gorilla arm
 n.

   The side-effect that destroyed touch-screens as a mainstream input
   technology despite a promising start in the early 1980s. It seems the
   designers of all those {spiffy} touch-menu systems failed to notice
   that humans aren't designed to hold their arms in front of their faces
   making small motions. After more than a very few selections, the arm
   begins to feel sore, cramped, and oversized -- the operator looks like
   a gorilla while using the touch screen and feels like one afterwards.
   This is now considered a classic cautionary tale to human-factors
   designers; "Remember the gorilla arm!" is shorthand for "How is this
   going to fly in real use?".
    

gorilla arm

   The side-effect that destroyed touch-screens as a mainstream
   input technology despite a promising start in the early 1980s.
   It seems the designers of all those {spiffy} touch-menu
   systems failed to notice that humans aren't designed to hold
   their arms in front of their faces making small motions.
   After more than a very few selections, the arm begins to feel
   sore, cramped, and oversized - the operator looks like a
   gorilla while using the touch screen and feels like one
   afterward.  This is now considered a classic cautionary tale
   to human-factors designers; "Remember the gorilla arm!" is
   shorthand for "How is this going to fly in *real* use?".