How a Virtual Agent Should Smile?

Morphological and Dynamic Characteristics of Virtual Agent’s Smiles
  • Magalie Ochs
  • Radosław Niewiadomski
  • Catherine Pelachaud
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6356)


A smile may communicate different meanings depending on subtle characteristics of the facial expression. In this article, we have studied the morphological and dynamic characteristics of amused, polite, and embarrassed smiles displayed by a virtual agent. A web application has been developed to collect virtual agent’s smile descriptions corpus directly constructed by users. Based on the corpora and using a decision tree classification technique, we propose an algorithm to determine the characteristics of each type of the smile that a virtual agent may express. The proposed algorithm enables one to generate a variety of facial expressions corresponding to the polite, embarrassed, and amused smiles.


Smile Embodied Conversational Agent (ECA) Facial Expression Decision Tree 


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  1. 1.
    Ekman, P., Friesen, W.: Felt, false, and miserable smiles. Journal of Nonverbal Behavior 6, 238–252 (1982)CrossRefGoogle Scholar
  2. 2.
    Rehm, M.: Catch me if you can – exploring lying agents in social settings. In: AAMAS, pp. 937–944. Academic Press Inc., London (2005)Google Scholar
  3. 3.
    Niewiadomski, R., Pelachaud, C.: Model of facial expressions management for an embodied conversational agent. In: Paiva, A.C.R., Prada, R., Picard, R.W. (eds.) ACII 2007. LNCS, vol. 4738, pp. 12–23. Springer, Heidelberg (2007)CrossRefGoogle Scholar
  4. 4.
    Krumhuber, E., Manstead, A., Cosker, D., Marshall, D., Rosin, P.: Effects of dynamic attributes of smiles in human and synthetic faces: A simulated job interview setting. Journal of Nonverbal Behavior 33, 1–15 (2008)CrossRefGoogle Scholar
  5. 5.
    Theonas, G., Hobbs, D., Rigas, D.: Employing virtual lecturers’ facial expressions in virtual educational environments. International Journal of Virtual Reality 7, 31–44 (2008)Google Scholar
  6. 6.
    Frank, M., Ekman, P., Friesen, W.: Behavioral markers and recognizability of the smile of enjoyment. Journal of Personality and Social Psychology 64, 83–93 (1993)CrossRefGoogle Scholar
  7. 7.
    Keltner, D.: Signs of appeasement: Evidence for the distinct displays of embarrassment, amusement, and shame. Journal of Personality and Social Psychology 68(3), 441–454 (1995)CrossRefGoogle Scholar
  8. 8.
    Harrigan, J.A., O’Connell, D.M.: How do you look when feeling anxious? Facial displays of anxiety. Personality and Individual Differences 21, 205–212 (1996)CrossRefGoogle Scholar
  9. 9.
    Ambadar, Z., Cohn, J., Reed, L.: All smiles are not created equal: Morphology and timing of smiles perceived as amused, polite, and embarrassed/nervous. Journal of Nonverbal Behavior 17-34, 238–252 (2009)Google Scholar
  10. 10.
    Ekman, P.: Darwin, deception, and facial expression. Ann. N.Y. Acad. Sci. 1000, 205–221 (2003)CrossRefGoogle Scholar
  11. 11.
    Ekman, P., Friesen, W.V., Hager, J.C.: The facial action coding system. Weidenfeld and Nicolson (2002)Google Scholar
  12. 12.
    Duchenne, G.: The Mechanism of Human Facial Expression. Cambridge University Press, Cambridge (1990) (1862)Google Scholar
  13. 13.
    Krumhuber, E.G., Manstead, A.S.R.: Can duchenne smiles be feigned? new evidence on felt and false smiles. Emotion 9(6), 807–820 (2009)CrossRefGoogle Scholar
  14. 14.
    Hess, U., Kleck, R.E.: Differentiating emotion elicited and deliberate emotional facial expressions. European J. of Social Psychology 20(5), 369–385 (1990)CrossRefGoogle Scholar
  15. 15.
    Tanguy, E.: Emotions: the art of communication applied to virtual actors. PhD thesis, Department of Computer Science, University of Bath, England (2006)Google Scholar
  16. 16.
    Ekman, P., Friesen, W.: Unmasking the Face. A guide to recognizing emotions from facial clues. Prentice-Hall, Inc., Englewood Cliffs (1975)Google Scholar
  17. 17.
    Poggi, I., Pelachaud, C.: Emotional meaning and expression in performative faces. In: Affective Interactions: Towards a New Generation of Computer Interfaces (2000)Google Scholar
  18. 18.
    Rakotomalala, R.: Tanagra: un logiciel gratuit pour l’enseignement et la recherche. In: Sloot, P.M.A., Hoekstra, A.G., Priol, T., Reinefeld, A., Bubak, M. (eds.) EGC 2005. LNCS, vol. 3470, pp. 697–702. Springer, Heidelberg (2005)Google Scholar
  19. 19.
    Breiman, L., Friedman, J., Olsen, R., Stone, C.: Classification and Regression Trees. Chapman and Hall, Boca Raton (1984)zbMATHGoogle Scholar
  20. 20.
    Faigin, G.: The Artist’s Complete Guide to Facial Expression. Watson-Guptill (1990)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Magalie Ochs
    • 1
  • Radosław Niewiadomski
    • 1
  • Catherine Pelachaud
    • 1
  1. 1.CNRS-LTCI, Télécom ParisTechFrance

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