This article describes the findings of a constructivist qualitative research study focused on students' perceptions of the learning experience and student communication in two cohorts of doctoral students. We also capture student perceptions of taking a merged course--that is, two previously closed cohorts taking a course together for the first time. The effect of this type of change in course structure is not discussed in the literature on cohort-based education. Findings indicate that the merged course challenged previously established cohort group norms. Students described a change in the nature of the learning environment that shaped student communication and trust within the classroom. The classroom environment was consistently less interactive than in prior semesters when the cohorts were instructed separately. This finding suggests strong, but rigid, elasticity of cohort student relationships.