This study examines user perceptions regarding the value of collaboration systems from a longitudinal perspective. Resource management support, coordination support, and evaluation support are highlighted as key aspects based on which the users form cognitions about collaboration system value. Based on technology acceptance model and expectation disconfirmation theory, we propose a model that examines the evolution of user cognitions from pre-usage to post-adoption stage. The results show that the basis on which users form their cognitions about collaboration systems change over time. At the pre-usage stage, coordination support was found to be the most important determinant of value. At the post- adoption stage, evaluation support assumed more importance. Further, at the post-adoption stage the impact of confirmation on usefulness perceptions is partially mediated by user perceptions regarding evaluation support, providing interesting insights on the cognition revision process. The study offers implications for research and practice.