[영문]This paper suggests a conceptual shift in the way we approach information sharing by foregrounding the role of categorization. We argue that the establishment of professional categories, while being central to institutional intervention, is contingent on the complexities of everyday inter-professional encounters. It is important therefore to analyse situations in professionals report on the negotiation of categories as well as how professionals account for a failure to align sender and receiver frames. The data analysed in this paper consists two excerpts each from a public inquiry in the UK (the Victoria Climbie Inquiry) and one in Belgium (the Parliamentary Commission Dutroux). In conclusion, we address a number of themes in contemporary debates about improving interagency and within-agency communication. In particular, we advocate the promotion of language awareness rooted in interactional analysis and the need to understand the on-the-ground dynamics of evolving everyday practice as important prerequisites for bringing about and responding to change.