Audience first - Means later

What communicates climate change science best? WRI is researching which method works better: web cam talk, conversation or whiteboard talk. You can watch three scientists present the findings of their studies, using each time a different method, and then vote. The answers however may depend very much on the intended audience: other colleague climate scientists (web cam?); students and academics (whiteboard talk?); politicians or general public maybe none of these, as there is no clear message and action perspective. This all illustrates the need in communication to define the audience first, then the behaviour change we are after (inlcudng the obstacles to get there), then the message and only at that point in time the communication means!