Main Idea

Why is it important? Main ideas help readers remember important information.

What is the purpose? The main idea of a paragraph tells the topic of the paragraph. The topic tells what all or most of the sentences are about.

The other sentences in the paragraph are called details. Details describe or explain the main idea.

Four Steps for Discovering the Main Idea 1. Identify the Topic 2. Identify the Main Idea statement -- Discover what the author wants you to know about the topic 3. Organize your Facts (supporting details) 4. Identify the author’s purpose – Why did the author write it?

Step 1: Identify the Topic Topic: The topic is the subject or focus of the paragraph. It is a person, place, event, idea, object, or happening being discussed. Here are two questions to ask yourself as you skim the passage: 1. What word or phrase does the author mention or refer to the most? 2. Is that word or phrase by itself specific enough to express the topic of the paragraph or does it need to be modified?

The following paragraph will give us some practice: 1 Scientists believe that tropical rain forests contain large numbers of plant and animal species still unknown to science. 2 Nevertheless, the rain forests of the world are being recklessly destroyed. 3 In order to grow more food, farmers burn down the forests and plant crops. 4 The nutrients in rain-forest soil, however, are quickly exhausted by farming. 5 Also, trees are being cut down for their timber faster than new trees can grow to replace them. What word or phrase does the author mention or refer to the most?

1 Scientists believe that tropical rain forests contain large numbers of plant and animal species still unknown to science. 2 Nevertheless, the rain forests of the world are being recklessly destroyed. 3 In order to grow more food, farmers burn down the forests and plant crops. 4 The nutrients in rain-forest soil, however, are quickly exhausted by farming. 5 Also, trees are being cut down for their timber faster than new trees can grow to replace them. "Rain forests" is the answer.

Before you answer, look carefully at each sentence in the paragraph. Is that word or phrase by itself specific enough to express the topic of the paragraph, or does it need to be modified? This paragraph doesn’t discuss everything related to rain forests – only its destruction. Instead, the focus is on the destruction of the rain forests. So, rain forests by itself would not be enough. Those sentences do not explore the many sub-topics that could fall under the heading "rain forests" – description of the types of plants or animals, the ecosystem, etc.

Step 2: Identify the Main Idea statement -- Discover what the author wants you to know about the topic Main Idea Statement: The main idea statement has lots of names – topic sentence, thesis statement, central idea, controlling idea -- but they all identify the same thing – the author’s point about the topic.

Main idea statements are more general than other sentences in the paragraph Main idea statements tell you what the author wants you to know about the topic. Therefore, the topic should be the subject of the main idea sentence! Main idea statements sum up the message of the paragraph or reading passage Here are some characteristics of main idea statements:

1 Scientists believe that tropical rain forests contain large numbers of plant and animal species still unknown to science. 2 Nevertheless, the rain forests of the world are being recklessly destroyed. 3 In order to grow more food, farmers burn down the forests and plant crops. 4 The nutrients in rain-forest soil, however, are quickly exhausted by farming. 5 Also, trees are being cut down for their timber faster than new trees can grow to replace them. Let’s look at our rain forest paragraph again: Based on our topic, sentence 2 is a possibility. Did you select sentence 2? Now, we’re ready for the next step. We already know that our topic is the destruction of the rain forests. What does the author want me to know? Is there one sentence in the paragraph that sums it all up? The first sentence acts as an introductory statement; it’s the first time the topic is mentioned, but it doesn’t tell us what the author wants us to know.

Step 3: Organize your Facts (supporting details) supporting details include "examples, reasons, facts, and other evidence 1 Scientists believe that tropical rain forests contain large numbers of plant and animal species still unknown to science. 2 Nevertheless, the rain forests of the world are being recklessly destroyed. 3 In order to grow more food, farmers burn down the forests and plant crops. 4 The nutrients in rain-forest soil, however, are quickly exhausted by farming. 5 Also, trees are being cut down for their timber faster than new trees can grow to replace them. Let’s look at the rain forest paragraph again: We’re pretty sure that our main idea statement is sentence 2, but let’s check our facts.

Okay, so we’ve already decided that sentence 1 is our introductory sentence. We think sentence 2 is our main idea statement. So, our facts add up. We have the right main idea! Yes. They provide examples of how the rain forest is being destroyed. That leaves sentences 3,4, and 5. What do these sentences do?

Step 4: Identify the author’s purpose – Why did the author write it? Now I happen to know that this is a textbook selection, so that gives me one clue about the author’s purpose, but let’s take a moment to consider the other two purposes. Some of the purposes for writing include to persuade, to inform, to entertain, or to critique. (PIE+C) There are some others, but these are the main ones. Some of you may think the writer is trying to persuade us about something to do with the rain forest, but if we look at our facts or supporting details, we see that the author is presenting factual information about the destruction of the rain forests, so the author’s purpose, is to inform us about this topic. What about persuading? Did the author try to get us to take some action or believe a certain way? Did this paragraph make you laugh? Did you get the idea that the author was trying to be funny? No, I didn’t either, so we can rule out to entertain.

Let’s practice!

Pets are often an important part of people’s lives. Different types of animals can be pets, ranging from reptiles to horses. One of the most common pets is a dog. Dogs serve a variety of purposes for humankind. One way dogs serve humans is they are great just for companionship. Many an only child has bonded with his/her “Fido,”thus having a willing and loyal friend to play with on a daily basis. Additionally, dogs have served humans as work animals, corralling sheep, conquering rats, and guarding the homestead. Finally, dogs also assist people, for example, by leading the blind, alerting the deaf, and alerting epileptics of impending seizures. In conclusion, a dog’s work is never done. 1. What is the topic? Dogs 2. What is the main idea statement? (What does the author want us know about dogs?)

Let’s look at each sentence and see what’s going on: “Pets are often an important part of people’s lives.” Now ask yourself: “Is this what the whole paragraph is about? Is the writer telling me that pets are important? The answer is “NO.” So this cannot be the main idea. “Different types of animals can be pets, ranging from reptiles to horses.” Is the whole paragraph trying to tell us about pets ranging from reptiles to horses? NO!

“One of the most common pets is a dog.” Is the whole paragraph about how common dogs are? NO! “Dogs serve a variety of purposes for humankind.” Does the paragraph tell us about the different purposes dogs serve for humankind? YES!!! Because the whole paragraph is telling us about the variety of purposes dogs serve for humankind, that’s the main idea!

You’re doing a terrific job! Let’s do one more.

Soccer players learn many skills when playing soccer. Soccer players learn how to dribble and pass the ball. They also learn how to control the ball so they can eventually score. Most importantly, soccer players learn how to work together with their teammates. What is the main idea? What is the topic? SOCCER Soccer players learn many skills.

A) They also learn how to control the ball so they can eventually score.A) They also learn how to control the ball so they can eventually score. B) Soccer players learn how to dribble. C) Soccer players learn many skills when playing soccer.C) Soccer players learn many skills when playing soccer.

ONE MORE...

There are many fun things to do at the beach. Swimming is one thing that can be done at the beach. Snorkeling is another thing that can be enjoyed. Playing beach volleyball can be a lot of fun. It is also fun to look for shells. Some people simply like to sunbathe. What is the main idea? What is the topic? Beach There are many things to do at the beach