This article draws on second language theory, particularly output theory as defined by Swain (1995), in order to conceptualise observations made in a computer-assisted language learning setting. It investigates second language output and learner behaviour within an electronic role-play setting, based on a subject-specific problem solving task and the Internet as source of primary information. Students were given a task which includes the collaborative development of a marketing strategy for a chosen product. Data collected consists of the following corpora: emails exchanged between groups, the recorded discussions between each group's members while engaged in the problem solving activity, oral presentation of the groups' results as well as the individually written summaries. One area of particular interest is the analysis of the oral L2 output while solving a computer-assisted language learning task. How can the oral interaction be characterised? What kind of conclusions regarding the use of CALL can be drawn from the comparison of the oral interaction and the written output? Another area of interest is the analysis of the written L2 output. Is there evidence of second language acquisition and/or acquisition of content? Can such a CALL setting promote second language acquisition (SLA) and/or acquisition of content? Finally, the study aims to identify whether student-initiated focus on language form can be found. The article answers the questions posed above. Furthermore, the results of this study show that a very high percentage of all communication took place in L2 and occurrences of acquisition of content and language can be demonstrated.