This article describes a case study of an international collaboration between two classes of fifth grade students through an online discussion platform with one group more experienced in online knowledge building activities than the other. Before the collaboration, the novice class tended to produce isolated notes filled with information and confined their efforts to their own selected topics. When the more experienced class joined in, the discourse of the students in the novice class changed from more information-centered toward meaning negotiations; many more of their notes were linked with one another and they no longer confined their reading and responses to their own study topic. The class more experienced in knowledge building was more ready to express disagreement in their discourse. There was also evidence that the novice class learned from the experienced class to ask more questions in their online discussion. When the joint-collaboration ended, the novice class could still maintain the changed interaction patterns that reflected a stronger knowledge building orientation. (Contains 3 tables.)