Social Presence Theory-- The perception of the interactants is based on the enabling or disabling of nonverbal cues afforded in the medium. If different cues provide different meanings and different channels transmit different cues in different degrees, finding the right channel for your message could increase your social presence.
Media Richness Theory-- a medium's "richness" depends on how much information it can carry. It is based on four criteria, 1) speed of feedback, 2) ability to communicate multiple cues, 3) the use of natural language instead of numbers and 4)the ability to convey feelings and emotions.
Social Identity Model of Deindividuism Effects (SIDE model) - Anonymity available via CMC leads to deindividuation and awareness of the self is lost. Then when one relates to other CMC conversant(s), it is through the group's identity and shared similarities. This yields a unified (one dimensional) perception.
Signaling - Adapted from the economic and biological fields, self-presentation claims can be evaluated via conventional (often verbal or written statements) and assessment signals (artifacts that relate factually). Lying is easier with only conventional signals, but comes at a cost.