Abstract
Peer-to-peer collaborative learning by means of online discussion is commonly used by teachers and in studies. However, a variety of current studies reveal that it has always been a common phenomenon that there is excessive amount of off-topic information in such discussion. Although off-topic discussion can be an ease in learning, excessive off-topic discussion will absolutely have adverse impact on discussion activities. In light of this, this study tries to design a mechanism that reduces off-topic discussion by means of filtration prompting strategy and self-reflection strategy in the hope that the occurrence of excessive off-topic discussion can be reduced through the operation of this systematic mechanism.