Internet Relay Chat (IRC) was the Internet’s first widely popular synchronous computer-mediated communication (CMC) system. While previous academic research has largely been content with demonstrations of the linguistic features of IRC, and is now turning to more structurally-oriented topics, it is argued in this paper that IRC research now needs to systematically address links between interaction structures and technological mediation within a framework that facilitates IRC interaction. This exploration of the exchange structures on IRC is positioned as a step in that direction.The data investigated in the study were those that occurred naturally on public IRC channels and approached from a Conversation Analysis - informed Discourse Analysis perspective. The analysis is primarily focused upon the interactional patterns and dialogue processes in relation to the IRC context. It is found that owing to deficient system interfaces, standard chatrooms are characterized by a high degree of disrupted turns, overlapping exchanges and addressing difficulties, which constitute potential hindrance to effective on-line communication. The study also determines that the chatters recognize a need to use their adaptive strategies to achieve better turn-positioning and avoid overlapping in their online transactions with others. The more obvious strategies include shortening or splitting their turns, which nonetheless hampers productive and meaningful interaction.In addressing the questions brought up in the above, this study sets out to identify the underlying reasons for these problems in the light of technological determinants. With particular reference to the role of the client interface, this paper advances a few preliminary suggestions oriented to enhance interactional coherence in chatrooms through the improvement of chat program design.