If writing is like making a movie, emphasis could be compared to a photographer's zoom lens, moving in for a close-up one moment and back for a wide-angle shot the next. Emphasis allows you to create similar special effects by magnifying, reducing, or even eliminating certain details. By controlling emphasis, you can focus your readers' attention on what is most important.
In speech we create emphasis by pausing or speaking louder, but in writing we don't have that opportunity. Still, besides underlining and using exclamation marks, you can focus attention by using selection, placement, and repetition.
Selection
If you've been using the discovery aids in Discovering What to Write you've probably noticed that you must constantly make decisions about what to include and what to leave out. Failure to make such decisions can cause you to get lost in irrelevancies. By keeping your purpose in mind, however, you have a basis for deciding what to say and what to leave out.
By controlling emphasis, you can focus your readers' attention on what is most important.
Simply because we have different personalities, purposes, and readers, we see some aspects of our subject as more important than others. Imagine, for instance, that two reporters have been sent to cover a tennis tournament: one is in the fashion department and one in the sports department of the local newspaper. Even if they spend most of their time together, their final reports will have little in common. The fashion reporter will concentrate on describing the clothing, hairstyles, and manners of the players and spectators. The sports reporter, on the other hand, will describe the shots made and missed, the players' energy cycles, anything that helps readers get into the feel of the action. Probably, though, the players' clothes will be mentioned only briefly if at all. The same thing happens, although perhaps in a more subtle way, in all writing. Simply because we have different personalities, purposes, and readers, we see some aspects of our subject as more important than others.
Placement
In any piece of writing—a sentence, a paragraph, an essay, a whole book—the first and last positions are vitally important. At the beginning of any of these units, the reader's mind is clear, fresh, and ready to absorb whatever it encounters. That's why the topic sentence of a paragraph so often comes at the beginning. Again, at the end of even so short a unit as a sentence, comes a place just before completion where expectations and attention are very high, where readers expect to get the essence of the message, the point of it all.
In any piece of writing-a sentence, a paragraph, an essay, a whole book-the first and last positions are vitally important.
By effective placement, we can take advantage of these expectations. We can use openings and closings as locations for concepts or facts that we want to highlight. Putting the topic sentence in the first position of a paragraph is a good example of using placement effectively, as is saving the most important detail for last rather than sandwiching it between two less important points where it could go unnoticed. Likewise, getting the most important words of a sentence up front focuses attention on them, while placing a key word at the end of a sentence will cause it to linger a while in the reader's mind.
Repetition
Repeat consciously, rather than unconsciously.
Used carelessly, repetition can weaken writing by making it monotonous and predictable, but effective repetition can strengthen writing by setting up reader expectations which can be satisfied or frustrated as you choose. For this reason and also because repetition puts key words and concepts before your reader more than once, you can use it to center attention on vital facts and thought patterns.
Probably you've already used repetition in your writing without realizing it. You won't necessarily strengthen your paper by adding more, and may weaken it. Use repetition sparingly. Repeat consciously, rather than unconsciously.