This book reports on a number of attempts to provide computer support for cooperative work and collaborative learning. Critical consideration of the problems exposed by these efforts leads to the formulation of the concept of group cognition as a view at the group unit of analysis. It suggests starting the Virtual Math Teams Project to analyze in detail how group interaction can achieve cognitive accomplishments. Analysis of small groups of students in a face-to-face setting and using AOL chat provides examples of how to study textual interaction, pioneering a method specifically designed for CSCL research.