What constitutes successful participation in discussion in French? The project combines qualitative and quantitative methods to determine what behaviours constitute successful participation in French debate among learners of French. After group discussions on polemical topics among advanced learners of the language were recorded in Australia, a group of French age-peers judged the exchanges on their relative success and on aspects of interactional behaviour including the extent to which participants advanced debate, dominated and/or supported each other. These aspects were identified prior to the evaluation through a comparative analysis of definitions of a successful and a failed discussion as provided by the participants. The Francophone assessments of the recordings were then analysed to determine which of these aspects correlated with the overall success of the exchange. Building on these results, and drawing on the principles of cross-cultural pragmatics, a multidimensional interactionist analysis of the most and least successful exchanges was undertaken to identify interactional strategies contributing to the success or failure of the exchanges. This involved focussing on the various phenomena and behaviour observable in the discussions judged most successful but absent in the least successful discussions, analysing the waveform representations of the audio-recordings to determine the sound atmosphere, analysing non-verbal behaviour, and undertaking a detailed micro-analysis of the transcription of these exchanges. Results showed that advancing debate through advancing and challenging opinions was most likely to lead to the Francophones judging the discussions as successful. The most successful discussions showed participants adopting a wide range of interchangeable interactional positions in which all could successively take the lead in discussion, and consistently questioning and elaborating opinions, thus placing a clear emphasis on the co-construction of ideas. Least successful discussions as seen by the Francophones showed greater concern for facework strategies and followed a stable pattern of opinions being offered in turn but not negotiated, leading to agreement rather than debate. The sound and visual atmosphere of the discussion was also directly connected to the success of the discussion: the non-verbal behaviour analysis showed that participants in successful discussions displayed an increased use of hand gestures and maintained visual contact between the participants while the waveform analysis underlined situations of brouhaha as a recurring component of the most successful discussions. The project departs from previous studies by focusing on discussion in French as a multilayered cultural practice and therefore undertaking a multidimensional analysis to ascertain the elements that correlate with its success or failure. The findings of the project will provide a better understanding of the cultural specificity of different interactional styles, and of the cultural anchoring of interactional strategies contributing to the success or failure of a discussion. It will serve as a potential basis for teaching interactional skills and pragmatic competence in French as a second language.