Much research in recent years has focused on the introduction of virtual learning environments (VLEs) to universities, documenting practice, and sharing experience (Armitage et al., 2001, Browne and Jenkins, 2003, Moron-Garcia, 2004, Weller, 2007). Attention has been directed towards the importance of online dialogue for learning as a defining feature of the VLE. Communicative tools are an important means by which VLEs have the potential to transform learning with computers from being passive and transmissive in nature, to being active and constructivist (Pavey & Garland, 2004). However, practical methods of reviewing and analysing online communication to trace cycles of real dialogue (and learning) have proved somewhat elusive. Qualitative methods are also under-used for VLE discussions, since they demand new sets of research skills for those unfamiliar with them, and can be time intensive. This paper describes a visualisation tool to aid the analysis of online communication. The tool has two purposes: first, it can be used on a day-to-day basis by teachers or forum moderators to review the development of a discussion and to support appropriate interventions. Second, the tool can support research activities since the visualisations generated provide the basis for further qualitative and quantitative analysis of online dialogue. The visualisation software is designed to encode interaction types simply and quickly. The software was tested and then used to analyse data from a sample of forums within the Moodle VLE. The paper discusses both the method of visualisation and analysis of the online interactions as a pilot for further research analysing interaction in discussion forums.