PART TWO
FINDING THE MAIN IDEA

This lesson will use and develop the information you have learned in Part One. Specifically, we will discuss how and where to find the main idea and how the paragraph is structured around it. Our emphasis will be on reading for main idea although concepts such as basic unit of meaning and topic sentence will also be explored.

A paragraph represents a basic unit of meaning. If this were not so, a letter to a friend or a job application could be written using one long paragraph, and an essay, a short story, or a novel could consist of one continuous paragraph. Obviously, this would be awkward and confusing. A paragraph, therefore, should express and develop one main idea. If a new main idea is introduced, it should be expressed and developed in a separate paragraph thus preserving each paragraph's basic unit of meaning.

A basic unit of meaning consists of one main idea explained and developed by minor ideas or supporting details.

The main idea of a paragraph is stated in what is called a topic sentence. A topic sentence expresses a concept whose full meaning and significance are developed and made clear by the supporting details.

More often than not, the topic sentence is the first sentence of a paragraph. It is followed by other sentences, containing supporting details, which explain, develop, or support the main idea expressed in the topic sentence. The topic sentence usually comes first in the paragraph for obvious reasons. The following example explains why:

You have had a long, hard day at school. Your first words as you open the door are, "I had a miserable day." This statement can be considered a topic sentence which expresses a main idea. You may then add supporting details which explain why your day was miserable. "My car wouldn't start this morning and I arrived late for an important exam. I'm sure the nervous state I was in will affect my grade. To top it off, Julie gave me the cold shoulder."

Newspaper articles follow the same design so that readers can look at the first few lines and decide if they want to continue with the story.

The following newspaper article is typical:

Africa—The fight against starvation in six West African nations is being hampered by the rainy season. Heavy rains are turning the dirt roads into muddy rivers. Relief will have to wait for a dry spell which seems nowhere in sight. The weather bureau is maintaining silence for fear of causing increased alarm.

The preceding paragraph can be represented by an upside-down or inverted triangle (▼) since it starts with a broad statement, the topic sentence, and continues with supporting sentences of diminishing importance.

The following diagram might be useful:

Sometimes a topic sentence is located at the end of a paragraph. Positioning the topic sentence at the end of a paragraph is common practice whenever a difficult or unpopular idea is discussed or when the purpose of the paragraph is to persuade and convince. It seems that readers are generally more receptive to a new idea if the reasons for accepting the idea are presented first.

A paragraph whose topic sentence comes last can be represented by a regular triangle (▲). Read the following paragraph carefully. Notice how the overall impact of the supporting ideas is calculated to convince the reader that the main idea expressed in the last sentence should be accepted.

Notice how the supporting details progress in order of least important to more important and how they all come together in the topic sentence at the base of the triangle. A well-told joke is constructed along the same general lines. The teller usually sets the stage for a joke by recounting a series of facts or events which progressively lead to an explosive punch line.

We have illustrated how a topic sentence can be the first or the last sentence in a paragraph. Occasionally, the topic sentence is located towards the middle of a paragraph. This style of paragraph can be represented within a diamond shape outline (♦). The following diagram is self-explanatory.

Naturally, the shape of the diamond would not be perfect if the topic sentence were the second sentence or the next to the last sentence of a paragraph. Even if the topic sentence were off-center, the paragraph would still be considered diamond-shaped.

Some paragraphs do not have a stated topic sentence. They are held together by an implied main idea, that is, one that is hinted at and not stated outright. In this kind of paragraph construction, the details, or supporting sentences, considered as a whole, comprise the main idea. The shape of this kind of paragraph is best represented by a rectangle ( ▊) since the paragraph does not build in any particular direction.

Since no single sentence stands out clearly as the topic sentence, the individual details must be interpreted and a main idea decided upon. The following main idea seems reasonable: Joshua, Bingham received an excellent education.

The object of this lesson was to review various aspects of main idea and paragraph structure, your ability to locate the main idea in a paragraph or in a series of paragraphs should serve you well in and out of the classroom.

The exercise which follows this lesson is designed to illustrate what has been discussed here. Read it carefully and refer back to these pages if you find it necessary.