Uses of communication

1) Urgent Issues – Issues that require you to quickly get ahold of someone, communicate and arrive at an action plan.
2) Complicated Issues – Topics that can not easily be summarized by a few sentences. Perhaps things like designing a new product or dealing with an intricate process.
3) Presence Awareness – Messages that require others to be absorbing the message instantly. For example, a faxed message assumes a person will get to it within several hours, perhaps days. An instant message (IM) assumes the person is on-line and available to read that message within a few moments.
4) Retention – The persistence of the message. For example, a phone conversation only stays around in the memory of the attendees whereas an email is documented until deleted.
5) Conveying Content – All the visual and contextual information about a message. Gestures, intonations, etc.