It has been argued that simple conceptualizations of usage are inadequate for understanding and studying use of complex information technologies. In this paper we contend that quality of use, instead of the dichotomy of use versus non-use, is appropriate for understanding the extent to which a complex information technology is being used. An inductive case study of the implementation of a complex information technology was conducted, which led to the development of a learning-based model of quality of use. This model suggests the inclusion of factors relating to training (either formal or informal), learning, and beliefs, their impact on quality of use, and their change over time. Moreover, it describes how quality of use evolves over time as learning increases and perceptions of the system change. Evidence from the case study, along with relationships from the literature, is provided to support the model. Implications for future research are also discussed.