A good piece of writing establishes and maintains a clear and appropriate direction. Your subject should clearly relate to the topic or assignment and suggest an assertion or a purpose for the essay. A subject should not be
- too broad
- too narrow
- too obvious
If your instructor asks you to write a review of an article on the use of computers in medicine, you shouldn’t review an article on computers in modern society even if it discusses their role in medicine; and, of course, you shouldn’t review an article totally off-topic, like one on computer imaging in space exploration.
Having chosen (or been assigned) a topic, you should stay on topic from beginning to end. In a review of computers in medicine, don’t drift into a discussion of the dehumanizing effects of life-sustaining technology in medicine — unless it relates directly to a point about computers. In the traditional expository essay, the focus is usually established by a thesis statement that occurs in the first paragraph. But this is not the only way to establish focus; a well-chosen title is often sufficient. For example, if your instructor permits, place the title of your review at the top of the paper (e.g., A Review of “Expert Systems in Medical Diagnosis,” James Moltke, Journal of Medical Diagnostics), and then commence directly with the business of summarizing and evaluating the article. This practice is acceptable as long as your purpose and direction are evident. In any case, make sure that your writing stays on track.
It will often help to think of your subject as not only a topic, but also a point of view about the topic, or an assertion. So instead of “computers in medicine” — which leaves your subject with a vague direction — try an seertion to further narrow your subject:
- computers benefit medicine
- computers benefit surgery through networking
- computers make contemporary medicine possible
Your assertion will lead to your purpose.