Zhiqiang Cai Arthur C. Graesser Keith K. Millis Diane F. Halpern Patricia S. Wallace Cristian Moldovan Carol Forsyth ARIES: An Intelligent Tutoring System Assisted by Conversational Agents. 796 2009 AIED http://dx.doi.org/10.3233/978-1-60750-028-5-796 conf/aied/2009 db/conf/aied/aied2009.html#CaiGMHWMF09