"Online communication is increasingly used in education, but it is not without problems. One significant difficulty is a lack of social presence. Social presence relates to the need for users of technology-based communication to perceive each other as real people. Low social presence can be a particular issue in text-based, asynchronous systems such as discussion forums, leading to feelings of impersonality and disengagement from online learning ..."
Via Alfredo Calderón, Mariano Fernandez S., juandoming