effectively). Other theories (social presence and "media naturalness") are concerned with the consequences of those media choices (i.e., what are the social effects of using particular communication media). Social presence theory (Short, et al., 1976) is a "seminal theory" of the viewed social effects of communications technology. And its main concern is, naturally, with telephony and telephone, but also even conferencing (and the research here was found among the sponsored by the General Post Office, now British Telecom). It argues that the social impact of a communication medium depend on the social presence it allows communicators to have. Social presence is defined as a property of the medium itself: the degree of acoustic, visual, and physical contact that it allows. The theory assumes that more contact will increase the key components of "presence": greater intimacy, immediacy, warmth and inter-personal rapport. As a consequence of social presence, social influence is expected to increase. In the case of communication technology, the assumption is that more text-based forms of interaction (e-mail, instant messaging) are less social, and therefore less conducive to social influence. Media richness theory (Daft & Lengel, 1986) shares some characteristics with social presence theory. It posits that the amount of information communicated differs with respect to a medium's richness. The theory assumes that resolving ambiguity and reducing uncertainty are the main goals of communication. Because communication media differ in the rate of understanding they can achieve in a specific time (with "rich" media carrying more information), they are not all capable of resolving uncertainty and ambiguity well. The more restricted the medium's capacity, the less uncertainty and equivocality it is able to manage. It follows that the richness of the media should be matched to the task so as to prevent over simplification or complication. Media naturalness theory (Kock, 2001; 2004) builds on human evolution ideas and has been proposed as an alternative to media richness theory. Media naturalness theory argues that since our Stone Age hominid ancestors have communicated primarily face-to-face, evolutionary pressures have led to the development of a brain that is consequently designed for that form of communication. Other forms of communication are too recent and unlikely to have posed evolutionary pressures that could have shaped our brain in their direction. Using communication media that suppress key elements found in face-to-face communication, as many electronic communication media do, thus ends up posing cognitive obstacles to communication. This