Interactivity is integral to media and communications and yet is a contested concept in the literature. There is little agreement on its meaning not least because of its multidisciplinary nature. Previous research, concerned with finding a single definition of interactivity, has focused narrowly on specific contexts of communication using limited methodologies. This thesis argues that several meanings of interactivity are in circulation and that the search for one bounded definition constrains understanding of its role and fails to recognise its analytical potential. The study makes an original contribution to research by presenting findings from an analysis of public discourses on interactivity, a valuable source of material neglected in research to date. It shows that at least nine thematic representations of interactivity are in circulation representing different aspects of its role in communicative events. These are identified as the Empowering, Commercial, Pedagogical, Aesthetic, Ludological, Futuropia, Hula-hoop, Sceptical and Information Society themes. The results are based on a longitudinal content and discourse analysis of fifteen years of newspaper coverage in Ireland, an original methodological addition to research, reflecting both a unique national perspective on the concept and the flow of influential international discourses within a small state. The content analysis draws a detailed quantitative picture of how and where interactivity arises in news coverage while the discourse analysis examines qualitative aspects of the dominant, overlapping and conflicting discourses around interactivity and the discourse communities operating behind the talk. The analysis illustrates how thematic representations of interactivity coexist both in discourse and in individual communicative events, suggesting the potential for layered interactivities in communication. The ‘age of interactivity’ describes a wide range of discourses from hype and myths around interactivity to its potentially transformative role in communication. Overall this thesis highlights the value of interactivity as a communication concept and analytical tool with rich research potential.