Measuring facial movement

A procedure has been developed for measuring visibly different facial movements. The Facial Action Code was derived from an analysis of the anatomical basis of facial movement. The method can be used to describe any facial movement (observed in photographs, motion picture film or videotape) in terms of anatomically based action units. The development of the method is explained, contrasting it to other methods of measuring facial behavior. An example of how facial behavior is measured is provided, and ideas about research applications are discussed.