This article reports results of a study that tracked growth factors in experiential training groups through Tuckman's conceptual framework of group development using Critical Incidents methodology and quantitative description. We sought to explore whether different growth factors varied in salience over the course of each of the groups' life and over time. Four group facilitators completed a total of 40 copies of the Group Development Checklist over the course of one academic semester. Results showed that growth factors varied across stages of group development and over time, offering partial support to Tuckman's model. We discuss several implications for training and future research on growth factors in experiential groups, as well as limitations of the study.