Effects of on-line collaborative argumentation processes on justifications

Justifications (through evidence or explanations) are central to productive argumentation. This study examines how the participant structures and discourse moves of students engaged in collaborative learning affect their justifications. Forty students working on Knowledge Forum, an on-line collaborative learning environment, posted 136 messages, which were coded and analyzed with an ordered logit, vector autoregression, system of equations. When students disagreed or made claims, they were more likely to use evidence. After a studentm ade an alternative claim, the next student posting a message was less likely to use evidence. When students made claims, disagreed, disagreed with other's justifications, or read more noet s, they were more likely to use explanations. Boys made more claims than girls did, but otherwise, they did not differ significantly in their likelihood of using justificatio.n Together, these results suggest that participant structures and discourse moves are linked to justifications.