The outcome of our 2009-10 tutorial session came up with several key themes that need to be thought about when communicating science. Based on discussion, we came up with the following mind-map:

What was most prominent was that different target audiences expect different things from science communication, with the language selection and delivery media being intrinsically linked to the target audience. I have re-drawn the mind-map into a more logical flow-chart style.
Based on our discussion, it is imperative that we consider our target audience. Here are a few examples of how to handle scientific communication with different audiences:
- General public
Definition: A wide range of people, some have higher education, others don’t. May not understand jargon that we take for granted.
How to present? You will lose reader interest if you are too technical too quickly and frustrate more knowledgeable readers if you are too simplistic. Ideal scenario is to introduce basic concepts first, providing a learning curve through an article. Think New Scientist science writing as an ideal example. - Experts
Definition: Very specialist niche of people, likely to have intimate knowledge of subject and of key jargon.
How to present? Readers will be very responsive to detailed in depth writing that is technically complex with lots of jargon terms. However, they will lose interest if the arguments presented are not concise and logically structured. - College level / new undergraduate students
Definition: School/college leavers that have a sound knowledge of basic concepts, understand basic jargon.
How to present? Best way is to still be relatively jargon free, but some concepts are readily accepted (down to personal judgement). Again, ensure arguments are concise and logically structured. In this bracket, it may pay dividends to be entertaining with your writing to maintain reader interest.
For a different perspective, from journalist Clive Cookson, see an article in the journal Ocean Challenge: Communicating science: Tips from a top journalist.