The purpose of this study was to describe preschool teachers' interventions during children's free play. A Weberian sociological framework was used to examine (1) what happens when teachers intervene into children's play, (2) teachers' beliefs and thus their decisions about play, and (3) the relationship between these issues. Three preschool teachers were video filmed during free play and later interviewed about observed intervention episodes. The teachers were prompted to talk about what happened during the event, what they were thinking about, and for what reason they intervened. Findings indicated that the intervention episode could be broken into three identifiable segments: antecedent, tactic, and consequence. The antecedents were categorized into one of four categories: breach of discipline, social isolation, child request, and reactive observation. The tactics were categorized as conversation participation, demonstration, environmental modification, praise, redirection, maintenance, and instruction. The consequences were noted as either changing play, not changing play, or undetermined. Teachers held differing beliefs and their actions were related to their belief systems. Teachers based their decisions upon their personal system of educational principles concerning how teachers should teach, how children learn, and the early childhood curriculum. Reasons for intervention fell into one of the three Weberian constructs: cultural influences, social-political influences, and economic influences. (Author/RH)