Diagrams are often conceived as static representations. In this paper, by contrast, we explore how conceptual graphic representations can be used as communicative devices for knowledge-intense activities in groups. We do so by reviewing and extending existing cognitive and communicative dimensions and criteria. The aim of our research is to formalize the description of diagrams used in management discussions, analyzing their communicative and collaborative functions in order to better use them in knowledge creation and sharing in teams. We start with reviewing and merging the literature on cognitive and communicative dimensions and the literature on boundary objects, as well as information visualization, in order to compile the most relevant dimensions for knowledge creation and sharing in team. Thus, we cluster those dimensions obtaining eight macro-dimensions. We propose a formal analysis of diagrams which can be used as a tool for selecting and modifying appropriate visualizations fordifferent knowledge-intensive activities in teams. An application example illustrates this approach.