Between February and May 1997, 58 sixth form students from Hong Kong were trained in the use of strategies during group discussions. Before the course began, questionnaires were completed by 24 practising teachers, and analyses of transcripts were taken during a pre-training discussion task. These identified the following key strategies which students need in order to play an effective part in discussion: seeking clarification, clarifying oneself, and checking that other people have understood one's message. Based on these findings, and on analysis of transcripts from the pre-training tasks, an action plan was drawn up, and teaching materials were developed which incorporated strategies designed to be used in training the students. The analyses indicated that learners made more attempts to seek clarification and to clarify themselves in the post-training discussion task than in the pre-training task. However, they also showed more incidents of ineffective than effective use of these strategies in the post-training discussion. While these results tended to support the value of strategy training, they raised two basic issues regarding strategfies-based instruction: (1) the necessity to support strategy training with linguistic scaffolding, and (2) the importance of peer help and co-operation in facilitating strategy use. Copyright © 2000 Oxford University Press.