This paper seeks to establish a set of concepts to help frame an empirical analysis of the relationship between internet communication technologies and political discourses. It discusses theoretical and methodological issues relating to established frameworks for investigating the role that these technologies play in politics. Specifically, it attempts to problematise notions of the internet as an extension of the public sphere, which we argue underestimate the role that individual users play in the co-construction of meaning. Additionally, we suggest, there are unresolved conceptual issues relating to the epistemological and ontological relationship between 'online' democracy and the 'offline' physical and social institutions through which democracy is enacted traditionally. We use the micro-blogging service Twitter to illustrate a series of methodological steps that, we argue, could facilitate an empirical investigation of internet-mediated conversation.