In the online collaborative environment, visibility is serious issue because learners aren’t co-located or even co-temporaneous, so other affordances must provide information about availability for social interaction. To increase sociability, the environment must provide a means for determining the presence of other community members and initiating spontaneous informal interactions (typically casual conversation, not task-based interactions)
The power of the presence indicator is that it offers the opportunity for impromptu communications – it says, “I am here.” It is a place where the mode of communication can be negotiated – “just send me an email,” or “let’s talk on the phone now,” and an informal message can even be left. It can overcome the sense of isolation that is so debilitating to the online learner. The doctoral student struggling with a statistics assignment at 3 AM can check who’s “up” and reach out for support and even, if she’s lucky, help with the assignment from the more statistically savvy of her classmates. There’s a sense of solidarity looking at a contacts list, and seeing who else is “up”, it is like seeing the lights on in dorm rooms down the hall. You can stick your head in a room and chat. We’re all up and we’re working away – all of this promotes a sense of social presence.
The effective use of a presence indicator is dependent on it being generated automatically when your computer is turned on, and on behavior – being scrupulous about keeping it updated. If you say you are available, then you need to be available. Signalling that you are busy or can’t be interrupted is perfectly fine, and part of the rules of engagement are that you respect the signals others have established.