Given the changing nature of work, much attention in recent years has been devoted to the skills students will need if they are to succeed in the knowledge economies of the 21st century. Success in these changing economies is very dependent on schools embracing these emerging changes and working with students to help them acquire the knowledge and skills they need to succeed. One approach to learning that has been extensively implemented over the last four decades is collaborative learning where students work in small groups on problem-based tasks. Success in these situations is very dependent on group members being willing to collaborate and communicate where they share ideas and information and acknowledge and challenge ideas and propositions in the context of being willing to engage constructively with others on the problem at hand. Building communicative skills can be a challenge if students are to not only work collaboratively but also think deeply about the issues they are discussing. This chapter discusses how to promote reasoning, problem-solving and learning in the context of collaborative group activities.