The Politeness Effect: Pedagogical Agents and Learning Gains. - Ning Wang 012; W. Lewis Johnson; Richard E. Mayer; Paola Rizzo; Erin Shaw; Heather Collins (AIED, 2005)

The politeness effect: Pedagogical agents and learning outcomes. - Ning Wang 012; W. Lewis Johnson; Richard E. Mayer; Paola Rizzo; Erin Shaw; Heather Collins (Int. J. Hum. Comput. Stud., 2008)