Designed as an analytic, exploratory inquiry into the manner in which preservice elementary school teachers make sense of their early science teaching performances, this study focused on how teachers exhibited a capacity for understanding pedagogy. Specifically, it concentrated on the reflective process as it occurred in the context of clinical supervision. The study took place in an elementary science methods course. Methods students taught science lessons to fourth, fifth, and sixth grade students in a Calgary, Alberta elementary school. The lessons were audio-taped and transcribed for analysis and clinical supervision techniques were used for the analysis of the lessons. Data indicated that preservice teachers can reflect, given the proper situation, and that the theoretical context of a methods course can be used for the reflective and diagnostic analysis of actual teaching. The concept of the cycle of reflection is also explored and implications for teacher education programs that promote reflection are noted. Transcripts of a lesson on environmental factors and a discussion of the lesson by the clinical supervisor and the teacher are appended. (ML)