As I work on essay skills with my GP groups, I find that it isn't the lack of content that's bringing down grades, but rather the overflow of content that overwhelms students and shocks them into mental paralysis. The misconception is that the more content goes into an essay, the better it will be graded; but quantity of content means nothing if it isn't relevant to the question.
It's all well and good to maintain a storehouse of knowledge, but selecting the most appropriate material from it quickly while disregarding the rest without guilt or doubt, and organizing the selected material effectively pays off more handsomely in an argumentative essay. After all, the objective is to win the argument, not confuse the situation any more than it already is.
For any argumentative essay, one fundamental requirement is to be able to have a general discussion on the concept in question. The simplest way to explain "concept" is to think of it as a short phrase that describes what the essay is about without any opinions or other preconceived notions about it. For example,
Q: The only role of the mass media should be that of a watchdog. Do you agree?
Concept: The mass media as watchdog.
Q: Does the Internet have a positive or negative impact on your society?
Concept: Social changes resulting from the widespread use of the Internet.
Q: Should people have the right to decide when and how they will die?
Concept: Human rights and the differences between suicide and euthanasia (asks a bit much of a miserable 800 word essay, I say)!
Notice that the concept can double as an unbiased title for the essay. Identifying the right concept gives us a handy guideline to help us decide if the content we select is relevant to our essay or not. What determines our stand (thesis) will depend on what our selection then leads us to believe about the concept we are discussing.
Hmm... I seem to be obsessing over GP this week. Guess I'll have to get it all out of my system before I go back to my regular nonsense. Bear with me, there's more but it's already quite late!