1 Probing the fuzzy concept of Flow: A longitudinal semantic analysis of Flow theory across multiple eras. W.Neill. University of New South Wales. william.neill@unsw.edu.au M.Burford. University of New South Wales. m.burford@unsw.edu.au A.Sinha. University of New South Wales. a.sinha@unsw.edu.au Keywords; flow, leximancer, experience, theory. Abstract Since the inception of flow theory in the 1970s with Csikszentmihalyi‟s work in positive psychology, ideas around flow have gained significant currency in a wide range of practical and theoretical applications. The developing ideas around an individual‟s optimal experience when immersed in a task are tracked across three broad year groupings of a sample of the flow literature relevant to marketing. Semantic and relational analysis revealed how an understanding of flow has matured over time, from discussions around happiness and social activities, through opportunities for engagement enabled by technology to the current situation linking flow more broadly to experience and positive performance outcomes. A conceptualization of the constructs underpinning flow capturing this rich history is then presented. Introduction The theory of flow, a notion of optimal experience that arises from an individual‟s interactions with a task (Jackson & Marsh 1996), is now approaching four decades of research in social science, where its diverse application to problems of prolonged engagement and intrinsic enjoyment have spawned considerable interest and discussion. However, what can we learn from the way it has developed over the course of its rapid maturation and adaptation? How can clearer insights into flow better inform our understanding of consumer interactions, particularly in online environments? More specifically, an interesting question remains as to how our present understanding of the concept of flow, with all its intertwined components, process variables and outcomes, can encapsulate the work that has gone before without loss of clarity or without overly diluting the historical richness of flow theory. To address this research question the researchers employ a semantic content and relational analysis tool, Leximancer, to analyse more than 130 selected articles. Articles are selected based on their citation of the central author Mihaly Csikszentmihalyi who founded flow theory in the mid - late 1970s. The aim is to better understand the changing literary landscape characterised by the linguistic associations and occurrence likelihoods of thematic terms associated within the flow literature. Papers are separated into discrete eras that then help explore the evolving discourse. Finally, a schematic representation of flow, based on Leximancer exploration of this corpus with researcher-derived flow constructs, captures current conceptualization of the meta-concept flow. Background Flow theory came to prominence in marketing theory through the work of Hoffman and Novak (1996). They suggested flow theory, being “in flow”, as a way for marketers to better understand consumers in the context of computer-mediated environments. This introduction positioned „flow‟ in marketing as a theory of interaction and psychological congruence