Jauwairia Nasir ^1,2* Barbara Bruno ^2,3 Pierre Dillenbourg ⁴

• ¹ Human Centered Artificial Intelligence Lab, University of Augsburg, Augsburg, Germany
• ² Swiss Federal Institute of Technology Lausanne, Lausanne, Vaud, Switzerland
• ³ Socially Assistive Robotics with Artificial Intelligence Lab, Karlsruhe Institute of Technology, Karlsruhe, Baden-Württemberg, Germany
• ⁴ Computer Human Interaction in Learning and Instruction Laboratory, Federal Institute of Technology in Lausanne, Lausanne, Vaud, Switzerland

When designing social robots for educational settings, there is often an emphasis on domain knowledge. This presents challenges: 1) Either robots must autonomously acquire domain knowledge, a currently unsolved problem in HRI, or 2) the designers provide this knowledge implying re-programming the robot for new contexts. Recent research explores alternative, relatively easier to port, knowledge areas like student rapport, engagement, and synchrony though these constructs are typically treated as the ultimate goals, when the final goal should be students' learning. Our aim is to propose a shift in how engagement is considered, aligning it naturally with learning. We introduce the notion of a skilled ignorant peer robot: a robot peer that has little to no domain knowledge but possesses knowledge of student behaviours conducive to learning, i.e., behaviours indicative of productive engagement as extracted from student behavioral profiles.We formally investigate how such a robot's interventions manipulate the children's engagement conducive to learning. Specifically, we evaluate two versions of the proposed robot, namely Harry and Hermione, in a user study with 136 students where each version differs in terms of the intervention strategy. Harry focuses on which suggestions to intervene with from a pool of communication, exploration, and reflection inducing suggestions, while Hermione also carefully considers when and why to intervene. While the teams interacting with Harry have higher productive engagement correlated to learning, this engagement isn't affected by the robot's intervention scheme. In contrast, Hermione's well-timed interventions, deemed more useful, correlate with productive engagement though engagement isn't correlated to learning. These results highlight the potential of a social educational robot as a skilled ignorant peer and stress the importance of precisely timing the robot interventions in a learning environment to be able to manipulate moderating variable of interest such as productive engagement.