There has long been a recognized need to measure the "success" or efficacy of information systems and the implementation process. Various constructs related to success have been suggested, such as user attitudes, system use, performance, and value. The attitude construct has received a great deal of attention for both theoretical and operational reasons. This paper focuses on the need for a convincing theoretical model linking systems or policies and user attitudes on the one hand, and user attitudes and performance or value on the other. Using job satisfaction research as a reference discipline for understanding the relationship between attitudes and performance, a model of IS attitudes, beliefs, and performance is developed. This model suggests that performance is affected by the correspondence or "fit" between the task requirements and the functionality of the IS environmenL In addition a distinction between beliefs and attitudes is recommended. While satisfaction might be best determined by measuring attitudes, the correspondence between task and functionality is best determined by measuring beliefs. The implications of this model for future research are discussed.