Finding the Main Idea: Reading Comprehension Review Study Guide (page 3)
Practice exercises for this study guide can be found at:
Just like speaking, writing is a form of communication. When you read a passage, the author of that passage is trying to tell you something. Otherwise, why would he or she go to the trouble of writing it? What the author is attempting to communicate to you is called the main idea of the passage. Simply put, the main idea is what a passage is mostly about!
Remember the question words in the previous chapter? Well, now's the time to think about that why question: Why is the subject of the passage even being discussed in the first place? In other words, what's the point? What does the author want me to know? Asking yourself why is a step in the right direction to finding out the point, or main idea.
NEXT TIME YOU read, ask yourself, "What's the point of this?" The answer will be very closely related to the main idea of the text.
SUBJECT VERSUS MAIN IDEA
Sometimes the subject of a passage and the main idea get confused. Let's talk about the difference. The subject is what the passage is about. For example:
Before a raindrop finds its way to the ground, it has already been on a long journey. Raindrops begin as water molecules that are in the earth's oceans, lakes, streams, and other bodies of water. As the sun heats the water, the molecules are evaporated up into the clouds. When there are a lot of water molecules gathered in the clouds, they get heavy and fall to the earth as raindrops. Some of those raindrops fall into the earth's oceans, lakes, and streams and the process begins all over again.
The subject of the passage is rain. It's about rain. But the main idea is not just what the passage is about; it's what the author says about the subject. So, if the subject is rain, what do you think the main idea would be? Reread the passage and see if you can figure out what is being said about rain.
Now that you've read it again, think about it. The author explains how water molecules evaporate into the air and form rain that falls and then starts the trip up again. So, the main idea would be something like how rain forms or the rain cycle.
The main idea is, quite literally, the central idea of a passage. All the rest of the text is made up of details that support, or tell more about, that main idea.
- subject = what the passage is about
- main idea = what is said about the subject
- detail = information in other sentences that support, or tell more about, the main idea
Let's look at another passage and see if we can distinguish the subject from the main idea.
In a lot of ways, having a digital camera is better than having a camera with film. For one thing, you can take many more pictures with a digital camera than you can with film. The digital camera holds the pictures on a small memory card. And because film takes up more space than the memory card, digital cameras are often smaller and easier to fit in a bag or pocket. In addition, a digital camera can be plugged directly into a computer, allowing the user to upload the pictures right after taking them and passing them on via e-mail. Film must be taken in to be developed, which is not only a slower process, but also ends up costing more money.
What's the subject of the passage? In other words, what's it about? That's easy, it's about cameras. But the main idea is a bit trickier. Again, the main idea is what is being said about the subject. So, what's being said about digital cameras and film cameras? Read the passage again and see if you can figure out what the main idea is.
One way to determine the main idea is to ask yourself, "What's the point?" and "Why does the author want me to know?" Well, the author seems to be expressing a preference for digital cameras over cameras that use film and giving details to explain why digital cameras are better. So, the main idea could be expressed as follows: Digital cameras are better. Of course, there are other ways to say it, but this is the main idea. Everything else in the passage supports one central, or main, idea.
BE CAREFUL. SOMETIMES the subject and main idea are very similar. Just remember that the main idea may include the subject, but will need support from details.
OFTEN THE MAIN idea is stated in the first sentence, so always check that sentence first.
Usually, the main idea of a passage is expressed in the topic sentence. Knowing this helps you identify the main idea. Usually, the topic sentence is the first sentence of a passage, but not always. To find it, here's what you do: Find a sentence that needs support. If all the other sentences support a sentence, then it's your topic sentence!
FUEL FOR THOUGHT
THE LONGEST SUSPENSION bridge in the world is the Akashi- Kaikyo Bridge in Japan. It spans 6,529 feet without any support from underneath.
For example, here's a sentence that doesn't need any help:
This is just a basic statement. It might be evidence for some greater issue, but we don't know that because it's all by itself. But here's a statement that does need help:
It can be dangerous to exercise in an atmosphere of extreme heat.
This isn't just your basic statement; it's an idea that needs some support. For example, how does the heat make it dangerous? What could happen to you if you exercise in those conditions? More explanation is definitely needed.
So you should remember that a topic sentence
- is often at the beginning of a passage
- is a sentence that needs support
- usually expresses the main idea of the passage
DON'T GET HUNG up on the idea of a topic sentence being the first sentence, because sometimes it won't be!
IMPLIED MAIN IDEA
Sometimes an author will not explicitly state his or her main idea. It seems strange: Why wouldn't writers want readers to know what the main idea is? Well, they do want the reader to know. Sometimes they just don't feel it's necessary to spell it out so clearly. You'll see this often in literature, where stylistic elements make it more important to imply the main idea rather than just come right out and say it.
FUEL FOR THOUGHT
HAVE YOU EVER listened to someone tell a story and thought to yourself, "What is the point of this?" It is probably because you didn't hear the main idea explicitly stated.
How to Find It
So, if it's not explicitly stated anywhere in the passage, how do you find out what it is? What you're going to do is look for clues. Think about what you have to work with. You don't have the main idea, but you do have the support for the main idea, so work backward. Read all the sentences and ask yourself, "What main idea are all these sentences supporting?" Look at the following paragraph.
Mrs. Framingham arrives at school early on Monday mornings so that she can set up her room for the week. Each week, she creates a new theme for her classroom to inspire her art students. Sometimes the theme will be people, and she'll hang portraits all over the room. Then she'll ask her students to draw portraits of each other and even themselves. When Mrs. Framingham teaches her students about sculpture, she takes them on an in-school field trip and carefully points out sculptural elements of the school's architecture and furniture.
As you might have noticed, this paragraph has no topic sentence. So how do you know what the main idea is? Be a detective. Ask yourself what all of the evidence in the paragraph could be supporting. Here's what we know: Mrs. Framingham arrives early on Monday morning. She seems to spend a lot of time thinking about how to inspire her students and uses creative ideas to help them learn. Based on this evidence, the main idea of the paragraph seems to be that Mrs. Framingham is a very dedicated teacher. This seems to be the point of the paragraph. When there is no topic sentence to explicitly state the main idea, you just want to uncover the point: What is it that the author is trying to say with regard to Mrs. Framingham?
FUEL FOR THOUGHT
SHERLOCK HOLMES IS a famous fictional detective created by the author Sir Arthur Conan Doyle. Be a detective like him and investigate what all of the evidence in a paragraph you read could be supporting.
PRACTICE WORKING BACKWARD by using the following three points of support to create a main idea:
- You can be social with your friends at the pool.
- Going swimming helps you cool off on a hot day.
- Being out in the sun provides your body with vitamin D.
Basically, the main idea of any piece of writing is the point that the author is making. So your task is to find out what that point is. To accomplish this task, you need to be able to differentiate between a subject and a main idea, because when you find the main idea, you've found the point. The subject of a passage is merely what is being talked about. What is being discussed? The main idea of a passage is what is being said about that subject. This is what you're looking to find out.
Oftentimes the main idea of a passage can be found in a topic sentence. A topic sentence will usually be at the beginning of a passage and will be a general idea that needs other ideas to support it. As you can see, identifying topic sentences can be a useful tool in finding the main idea.
But what happens if there isn't a topic sentence and nowhere in the passage is the main idea explicitly stated? How do you find it? You need to ask yourself, "What is the author's point?" Use the information you do have to lead you to the main idea. Determine what larger idea all the smaller ideas seem to support.
Practice exercises for this study guide can be found at:
- Kindergarten Sight Words List
- First Grade Sight Words List
- 10 Fun Activities for Children with Autism
- Definitions of Social Studies
- Grammar Lesson: Complete and Simple Predicates
- Child Development Theories
- Signs Your Child Might Have Asperger's Syndrome
- How to Practice Preschool Letter and Name Writing
- Social Cognitive Theory
- Theories of Learning