The influence of one teacher's scaffolding moves on children's performance in free-flowing child-led small-group discussions was investigated. Three moves were examined: prompting for and praising the use of evidence, asking for clarification, and challenging. Lag sequential analysis was applied to a corpus of over 5,300 speaking turns during 30 discussions to identify recurrent turn-by-turn patterns of teacher-child and child-child talk initiated by the teacher's moves. A complex system of influence among discussion participants was documented in which the teacher's moves had delayed effects as well as immediate effects, indirect as well as direct effects, and reciprocal instead of unidirectional effects. Some children appropriated scaffolding moves of the teacher and began to spontaneously employ the moves in later discussions. (Contains 1 note, 6 tables, and 5 figures.)