Michelene T. H. Chi Stephanie Siler Heisawn Jeong Takashi Yamauchi Robert G. Hausmann Learning from human tutoring. 471-533 2001 25 Cognitive Science 4 http://dx.doi.org/10.1016/S0364-0213(01)00044-1 db/journals/cogsci/cogsci25.html#ChiSJYH01