Ten six- and seven-year-old British children were chosen for case study investigation of the importance of children's interactions with each other and with their teacher in launching writing through sustained speech. The school was identified by educational experts as one of the "progressive" or "informal" variety, where children do considerable creative work in painting, drawing, and writing. The school was also identified as using "language experience methods" in teaching reading and writing. Classroom observations were made from mid-February to mid-May 1980. A total of 43 writing episodes was observed. Specific warranted conclusions relating to the development of sustained discourse are as follows: (1) where small writing groups are allowed to work on writing assignments together, group interaction facilitates solo discourse and sustains ideas in the prewriting and composing phases of a writing episode; and (2) the nature of group interaction, where groups are allowed to form and work together in a class, provides significant variables in selecting writing modes and affects the understanding and interpretation of assigned writing. (RL)