Metacognitive scaffolding in a computer-supported learning environment can influence students' metacognitive activities, metacognitive knowledge and domain knowledge. In this study we analyze how metacognitive activities mediate the relationships between different avatar scaffolds on students' learning. Multivariate, multilevel analysis of the 51,339 conversation turns by 54 elementary school students working in triads showed that scaffolding has an effect on students' learning. Students receiving structuring or problematizing metacognitive scaffolds displayed more metacognitive knowledge than students in the control group. Metacognitive activities mediated the effects of scaffolding, and increased metacognitive activities supported students' metacognitive knowledge. Moreover, students who were engaged in proportionately more cognitive activities or fewer off-task activities also outperformed other students on the metacognitive knowledge test. Only problematizing scaffolds led to more domain knowledge and metacognitive activities mediated the effects of the problematizing scaffolds. Moreover, students in the problematizing condition who engaged in more cognitive activities or whose group mates used more relational activities had greater domain knowledge acquisition than other students.
Keywords: Elementary education; Embodied agents; Metacognition; Scaffolding.