Social network sites are now ubiquitous and self-presentation on these sites is, for many people, a major part of everyday life. The sites provide a novel context for impression management in which presentations can be viewed simultaneously, 24 hours a day, by multiple audiences with heterogeneous expectations. The argument outlined here is that this situation can increase the chances of social anxiety and regulatory behaviour when these expectations are not met. Through four studies including two experiments, a survey and a collection of semi-structured interviews, this thesis examines the process by which users regulate their actions both on- and offline with respect to multiple audiences online. A model is created out of intrapsychic theories grounded on Carver and Scheier’s (2001) selfregulatory process, in order to explain impression management in this context. Research is split into two phases and addressing young users aged predominately aged from 18-24; the first aiming to provide support for different components within the model and the second, to test the process as a whole. Phase 1 finds strong support for the model by providing evidence, first for the assumptions underlying the multiple audience problem and second, that public self-focus increases when engaged with the technology. A third contribution of Phase 1 is its categorisation of preventive and reactive regulatory behaviours. Phase 2 supports the process in the model, showing that self-focus leads to comparison between what is presented and the standards of multiple audiences, resulting in self-regulation mediated by anxiety.

This thesis explores the nature of communication in television documentary, based on an investigation of production, reception and their interrelationship. It assumes that social context is fundamental to an understanding of mass communication. Doise's (1986) levels of analysis (intrapersonal; interpersonal/situational; positional; cultural/ideological) provide the framework for conceptualizing social context. Audience reception research, which appreciates viewers' active role in reception and influence on production, inspires the qualitative approach. Whilst these premises challenge a traditional transmission approach to mass communication, the thesis argues against simultaneously rejecting the concept of information transmission. The thesis is located within a ritual approach to communication (Carey, 1989), exploring the potential for information transmission by extending this approach to situational and positional levels. As a distinctive information genre, the television documentary is perfect for investigating transmission. In this endeavour, the thesis explores the assumptions of both broadcasters and audiences concerning the function, structure and content of documentary communication. The methodological structure comprises three qualitative studies - production context, reception context and a case study. The production study involves twenty one interviews with television documentary broadcasters and establishes two intersecting dimensions embracing their perspectives. The reception study includes eight focus group discussions, and finds documentary expectations differing by socio-economic status and gender. These studies provide the context for analysing the nature of communication in one documentary programme, "Parental Choice", comparing a producer interview with four audience focus group discussions. The results highlight a lack of awareness amongst broadcasters of the varying genre-specific criteria used by documentary audiences in programme interpretation. Information transmission is possible if viewers accept a documentary's credibility. However, perceptions of credibility vary at the situational and positional levels, thus transmission is limited and ritually-based. The emerging nature of documentary communication contributes to academic debate on mass communication, audience research and the television documentary genre.