Research, design, implementation, and evaluation of CALL materials needs to be based on sound SLA theories and research. A research agenda of CALL issues needs to be identified and investigated by means of suitable methodology. I propose that a Sociocultural approach to language learning provides a useful theoretical framework to investigate the process of collaborative activity in computer-mediated tasks. Following a brief overview of Sociocultural theory in relation to its claims about the usefulness of collaborative activity in the language classroom, I provide an account of issues to be addressed in task design. Finally, I exemplify from a study currently taking place how collaborative activity in computer-mediated tasks can be empirically studied, and I outline some of the methodological considerations underpinning such research work.