EXPLORING IT-BASED KNOWLEDGE SHARING PRACTICES: REPRESENTING KNOWLEDGE WITHIN AND ACROSS PROJECTS Drawing on the social representation literature combined with a need to better understand knowledge sharing across projects, this research lays the ground for the development of a theoretical account seeking to explain the relationship between project members’ representations of knowledge sharing practices and the use of knowledge-based systems as boundary objects or shared systems. The concept of social representations is particularly appropriate for studying social issues in continuous evolution such as the adoption of a new information system. The research design is structured as an interpretive case study, focusing on the knowledge sharing practices within and across four project groups. The findings showed significant divergence among the groups’ social representations. Sharing knowledge across projects was rather challenging, despite the potential advantages provided by the knowledge-based system. Therefore, technological change does not automatically trigger the intended changes in work practices and routines. The groups’ social representations need to be aligned with the desired behaviour or patterns of actions.