This volume presents research findings on the use of technology to support learning and reasoning in collaborative contexts. Featuring a variety of theoretical perspectives, ranging from sociocultural to social psychological to information processing views, Collaborative Learning, Reasoning, and Technologyincludes an international group of authors well known for their contributions to research on technology learning environments. Two themes are central: the use of technology as a scaffold for learning, and the use of technology to promote argumentation and reasoning. Collaboration among peers is a key element in both of these strands. These foci highlight, respectively, a key element in the design of technology-based learning environments and a key outcome that can result from online instruction/learning. As a whole, the volume addresses some of the core issues in using technology to support collaborative learning, reasoning, and argumentation.