text: The Facial Action Coding System was created by Prof. Thomas Huang of the University of Illnois and Prof. Nicu Sebe of the University of Amsterdam. The FACS first costructs a 3-D model of the face with all 44 face muscles. Movement of one or muscles is called an action unit. Dr. Paul Eckman, another creator of FACS, has "classified six basic emotions: happiness, surprise, anger, disgust, fear, and sadness, and then associated them with charactersitic movements of the facial muscles." The FACS was tested on the Mona Lisa, and detected her as "83 percent happy, 9 percent disgusted, 6 percent fearful, and 2 percent angry." A computer being able to understand human emotion would be groundbreaking, as "most human communication is nonverbal, including, emotional communication." We as humans have a variety of expressions, from huge ones to very subtle changes in mood. Computers need to understand these, along with the subtle facial movements that go with them. A extensive calculation is needed in order to acheive this goal. We humans perform this 'calculation' every day, as we can tell how a friend is feeling by the look on their face by taking their facial cues into consideration of their emotion. A comptuter that could a similar thing as such would know when you're happy or sad, and then react accordingly. If you were to smile at a Web ad, it would send a similar one. But if you frowned, the next one would be different. "A classroom computer could recognize when a student is becoming confused or bored," Dr Hunag predicts. "Then it could modify the lesson, like an effective human instructor." This would allow for a better learning environment and teaching skills for students.