Maintaining Clarity and Coherence

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The next example illustrates how writers can help readers follow a classification system by maintaining clarity and coherence—even when the subject is new and difficult. The passage comes from a book on physics by Gary Zukav. He uses classifying to explain the concept of mass. Simply defined, mass in physics is a measure of the matter in an object:

There are two kinds of mass, which means that there are two ways of talking about it. The first is gravitational mass. The gravitational mass of an object, roughly speaking, is the weight of the object as measured on a balance scale. Something that weighs three times more than another object has three times more mass. Gravitational mass is the measure of how much force the gravity of the earth exerts on an object. Newton’s laws describe the effects of this force, which vary with the distance of the mass from the earth. . . .

Zukav explains the concept of mass by classifying it into two types—gravitational and inertial—and provides cues to help readers understand the classification.

The second type of mass is inertial mass. Inertial mass is the measure of the resistance of an object to acceleration (or deceleration, which is negative acceleration). For example, it takes three times more force to move three railroad cars from a standstill to twenty miles per hour (positive acceleration) than it takes to move one railroad car from a standstill to twenty miles per hour. . . . Similarly, once they are moving, it takes three times more force to stop three cars than it takes to stop the single car. This is because the inertial mass of the three railroad cars is three times more than the inertial mass of the single railroad car.

—GARY ZUKAV, The Dancing Wu Li Masters: An Overview of the New Physics

General strategies for coherence are discussed in Chapter 13.

From this passage, we can see some of the cues writers use to make a classification clear and coherent. Zukav begins by forecasting the classification he will develop (There are two kinds of mass). He then introduces each category in its own paragraph, announced with a transition ( first and second) and presented in the same sentence pattern (The first is . . . and The second type of mass is . . .). Careful cueing like this can help make a classification clear to readers.

EXERCISE 17.3

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Look back at the paragraphs from Patricia Lyu’s essay on attachment that you used to make a tree diagram in Exercise 17.1 or at the example by Begley and Brant earlier in this chapter to examine the strategies these authors use to make their classifications clear and coherent. Notice how each category is introduced and how transitions are used to help readers keep track of the categories. What conclusions can you draw about how writers maintain clarity and coherence from your analysis?

Question

EXERCISE 17.4

Look back at the classification you examined in Exercise 17.2 to see how well you were able to maintain clarity and coherence in your classification. What changes would you make, if any, to improve clarity and coherence?

Question