Language Arts

When The Main Idea is Stated

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How do you identify the stated main idea of a paragraph or passage? Most of the time when you read in real life, you are reading pieces that are longer than a paragraph. Most of the time when you are taking a test of your reading comprehension, you are reading paragraphs. A paragraph is a unit of writing that is longer than a sentence and shorter than an entire essay or story. Paragraphs vary in length and style, but most paragraphs contain a sentence (called the main idea sentence by some, and more confusingly the topic sentence by others) that states the main idea of the paragraph.

There are several places that a stated main idea can be located in a paragraph or short piece. More often than not, the main idea sentence is the first sentence of a paragraph. It can sometimes be the last sentence, and occasionally it is in or near the middle. Since the main idea sentence states what the paragraph is about, the rest of the sentences expand the topic by giving details, reasons, examples, etc., to flesh out the paragraph.

Remember to look first at the beginning sentence of a paragraph to see if it sounds like a statement that covers the main point of the piece. Remember, the main idea sentence will be a statement that covers the entire paragraph. It has to be broad enough to encompass the entire paragraph, yet focused enough to be about the real point of the paragraph. If the first sentence does not sound like the main idea sentence, then look at the other sentences in the paragraph.

For a paragraph to be complete, it should contain information that supports, illustrates, or elaborates the main idea and the main idea sentence or the topic sentence. These are some ways that topic sentences may be developed:

By facts - Among other places, you will find this technique used in science and social science textbooks. The factual details clarify what was stated in the topic sentence.
By examples - This technique uses specific examples to support the generalized truth introduced in the topic sentence.
By an incident - This technique uses an elaborate example like an anecdote or brief story.
By comparison or contrast - Sometimes a topic sentence states that two things are either alike or different. The rest of the paragraph supplies details that show how those things are alike or different.
By reasons - This technique is often used when the purpose of a paragraph is to persuade or to argue a point. The writer would choose reasons that support his or her point of view. Any opposing points would be refuted.
By definition - This technique defines and explains key words or phrases from the topic sentence.
By combinations of the above.

Find the topic by asking yourself, in general, what is this about? Make sure your answer is broad enough to include all that the author talks about in the passage. Find the most important point the author is trying to make. To do this, find the major supporting details by looking for sentences that point the piece in a certain direction. Do not include every idea. The topic and the most important point = the main idea. Now, think about what the details are saying about the topic. What is the point the sentences together are trying to make? You will arrive at what will be the main idea.

Always be sure to think about what the details are saying about the topic. Always ask yourself, "What is the point these sentences together are trying to make?" Sometimes, really, quite often, a piece of writing will not have a sentence that you can point to that is the main idea. These are called "implied main ideas" and we will take a look at them in the next page. For now, let's practice a bit with stated main ideas.

When taking an exam, you will have to read a passage of information and answer questions based on the text. One tip would be to skim the questions to give you purpose for reading. The questions are asking: Which of the following is the topic of the paragraph, and which of the following best expresses the main idea of the selections?

Now, read the passage with those questions in mind.

Machines and tools have always been created in the image of man. The hammer grew from the balled fist, the rake from the hand with fingers outstretched for scratching, the shovel from the hand hollowed to scoop. As machines became more than simple tools, outstripping their creators in performance, demanding and obtaining increasing amounts of power, and acquiring superhuman speed and accuracies, their outward resemblance to the natural model disappeared; only the names of the machines' parts show vestiges of their human origin. The highly complex machinery of the industrial age has arms that swing, fingers that fold, legs that support, and teeth that grind. Machines feed on material, run when things go well, and spit and cough when they don't.

Now that you have read with a purpose, answer the questions:

Which of the following is the topic of this paragraph?

The highly complex machinery of the industrial age has arms that swing, fingers that fold, legs that support, and teeth that grind.
Machines' relationship to the human form.
The toughness of machines.

The answer would be b. Machines relationship to the human form. The remaining options are details that reinforce the topic.

Answering the next question: Which of the following best expresses the main idea of the selections?

The tools that we use in our daily lives have nothing to do with the design of the human body.
Archeologists have found no similarity between the tools of ancient times and the tools of today.
The tools that we use actually resemble human body parts except that they are even stronger and more effective.

The answer is c. The tools that we use actually resemble human body parts except that they are even stronger and more effective.

Let's try this again. Remember to scan the questions first. When reading this paragraph, you are looking for the topic and the main idea.

When someone mentions the word cockroach, what do you think of? If you are like most people, it is not a pleasant thought. However, despite the hatred that most people feel toward cockroaches, they do help humans in many ways. For example, they are perfect experimental animals and are used for scientific research in the laboratory. Scientists use roaches to help them study cancerous tumors because roaches grow tumors similar to those found in humans. Also, breeding them is easy because they thrive under almost any conditions. In fact, it is said that cockroaches could even survive a nuclear bomb. Since cockroaches will eat just about anything, they also make good test subjects to study food and nutrition. Long live "la cucaracha"!

Now, let's answer the questions:

The topic is…

Cockroaches.
How cockroaches help humans.
Cockroaches are nasty.
Long live the cockroach.

The topic is b. How cockroaches help people. Options a, c, and d aren't broad enough to be the topic. They are details. The main idea is found in the second sentence. Scanning the questions and answers prior to read the text can give you a purpose for reading and make answering the questions correctly easier.

The main idea is found in…

Sentence 1
Sentence 2
Sentence 3
Sentence 4

In the example provided, the main idea is directly stated in the third sentence. That is not always the case. Sometimes the main idea is not directly stated. Let's take a look at some examples where that is the case.