For this journal entry, I'm looking at the question, "How is the decision-to-link an issue of audience identification?" This also ties into the issue of how much to link.
As with any writing, you have to consider your audience's knowledge base. If they don't understand what you are saying, your message will be lost, no matter how well you say it. (For example, consider the popular show "ER" - how many people know, when they first see it, what the doctor means when he asks for an "ABG"?)
This applies to linking too. Links are used to further your message, to add context and meaning. If the audience knows what a term means, and it isn't a central theme, don't worry about linking it. But if the audience doesn't know, a link to explain would be appropriate.
Consideration of your audience is one of the most important aspects of writing. You have to anticipate your audience - get inside their heads, know what they know, want what they want. Then, go after that - fulfill the wants, build off of the knowledge. Use the audience analysis to weave your argument.