This research probes the content and consequences of the decisions that teachers make while conducting a lesson. Subjects included 2 middle school teachers (grades 7 and 8) and 35 of their students. This research employed participant observation, informant interviewing, and shared viewing of a videotaped lesson to explore interactive decision making. Analysis of the data collected resulted in a reconceptualization of interactive decision making as classroom reflection-in-action. The findings created categories of reflective actions for students and teachers, offered reasons for these actions, and explored the consequences. Cumulatively, the findings establish the complexity and ecological nature of classroom reflection-in-action and suggest additional areas for research. Thirty-five references are included. (IAH)