Technological advances in the last decade have impacted delivery methods of university courses. More and more courses are offered in a variety of formats. While academic rigor is a term often used, its definition is less clear. This mixed-methods study explored graduate student conceptions of rigor in the online learning environment embedded within blended courses. An initial survey revealed low correlation between student perceptions of rigor and learning, but high correlation between perceptions of learning, course organization, and clarity of expectations. Follow-up focus group interviews clarified graduate students' conceptions. The responsibility for rigor requires a critical partnership between teachers and learners.