Federico Tajariol Jean-Michel Adam Michel Dubois Seeing the Face and Observing the Actions: The Effects of Nonverbal Cues on Mediated Tutoring Dialogue. 480-489 2008 Intelligent Tutoring Systems http://dx.doi.org/10.1007/978-3-540-69132-7_51 conf/its/2008 db/conf/its/its2008.html#TajariolAD08