MetaTutor: Analyzing Self-Regulated Learning in a Tutoring System for Biology. - Roger Azevedo; Amy M. Witherspoon; Arthur C. Graesser; Danielle S. McNamara; Amber Chauncey; Emily Siler; Zhiqiang Cai 002; Vasile Rus; Mihai C. Lintean (AIED, 2009)