Channel expansion theory is a theory of communication media perceptions that incorporates experiential factors to explain and predict user perceptions of the new communication media. The theory suggests that in order to understand users' varying perceptions of any medium, we need to consider users' prior knowledge-building experiences relating to use of the same medium. Carlson and Zmud, who developed the theory in 1999, identified the following four experiences as important in shaping individuals' perception of media richness: experience with the channel, experience with the message topic, experience with the organizational context, and experience with communication partner.
Channel expansion theory Wikipedia
Channel expansion theory builds from a variety of theoretical perspectives that address perceptions of media channels. It combines elements from media richness theory with the social influence model that suggests that group member’s media perceptions and use align with those of the rest of the group members. At the root of media richness and channel expansion theories is media naturalness theory that suggests that most people have the n that media that suppress face-to-face communication elements (e.g., the ability to use tone of voice) pose obstacles for the effective communication of knowledge. According to media naturalness theory, for example, students learning about school subjects online will perform more poorly in tests covering those subjects than students learning about the same subjects face-to-face. Carlson and Zmud, in turn, predicted that users of unnatural media will adapt to those media in a compensatory way, and thus developed a theory of channel expansion. Essentially, channel expansion theory suggests that perceptions of communication channel are likely to vary across users and explains the variation by incorporating one particularly important factor that has not been considered prior – media use experience. By acquiring knowledge-building experiences in four domains (channel, topic, partner, organizational context) identified in the theory, users will have increased ability to communicate effectively in various situational contexts and will thus perceive the channel as being richer. It is important to note that what Carlson and Zmud conceptualized as relevant experience in channel expansion is not just the length of time of channel use, but the nature of that use and the bases of knowledge developed through it.
The channel expansion theory can be applied for organizational communication. Early conceptualization of organizational media use focused on media characteristics as primary determinants of users’ communication experience: social presence theorists argued that users' experience interacting via a particular channel depends on how co-present medium allows communicators to feel. Media richness theorists focused on the objective dimensions of media richness and the need to match the degree of medium richness with the message equivocality for effective communication. Channel expansion theory moves away from objective conceptualization of media and suggests that user’s perceptions of media richness are dependent on users prior experience with the channel. In this sense, the more knowledge-building experiences users acquires with a given channel (context, partner, and topic) the richer will be their perceptions of the medium and the more likely they will be to use it effectively. For organizational managers, the theory demonstrates that communication effectiveness and choice of communication media is bounded by user’s communication experiences, thus in order for the organizational employees to become proficient on a given communication channel and in a given organizational context, they must go through learning process to maximize the media communication richness potential. Additionally, the theory is associated with the level of the communicator’s ability to appropriate the medium to achieve shared understanding with communication partner; as perception of media richness improves with the acquired experience it has a positive effect on use richness – how much users employ various features of a communication channel. As individual users vary in how they utilize different features of media channels in their communication processes there is also a need for some form of training to continuously support users as technical features and communication capabilities of the channel expand (channel becomes richer). The most profound implication the theory has for individual media users is that it places great emphasis upon building knowledge rather than just simple experiences with media channels; if users wish to enhance effectiveness of a media tool they should acquire knowledge about its characteristics and capabilities rather than just use it repeatedly.
Channel expansion theory has been criticized for being originally applied to a single medium - email - and not having tested whether it operates similarly for more traditional media (like telephone) or advanced technologies (like videoconferencing). Another shortcoming of the theory noted in literature is that the developers of the theory (Carlson and Zmud) did not examine whether different forms of knowledge obtained through relevant experiences they identified may be impacting different richness dimensions. Finally, the theory overlooks the constraints that channels' inherent technological features may pose on the ability and degree to which media richness can "expand": even if knowledge-building experiences will enhance media perceived richness, it does not guarantee that the media can be objectively used as richer because of its capability constraints (like lack of video/audio, sensory etc.).