How do I Teach Main Idea?

  • 10 November, 2018

Teacher question:

Last week, I read your blog about how to teach theme to students by having them track character changes across a story and determine what lesson the character learns to determine the overall theme. Can you offer advice on determining the main idea of an informational text? Specifically, for third grade, students must determine the main idea, recount the key details and explain how the key details support the main idea. What is the best way HOW to teach this to third graders? 

Shanahan response:

Teaching “main idea” might seem simple, but it’s actually kind of complicated.

Not everyone even agrees on what label to use. Are we talking about main ideas, central ideas, purposes, topics, central messages, or themes? I dealt with that vexing confusion previously

No need to retread that mushy ground today. Let’s just assume you mean what I mean when it comes to main ideas (and if there is any doubt, just read that previous blog entry).

But even when we agree on what a main idea is, there are lots of differences in what is taught in pursuit of main idea. In an examination of main idea instruction (Jitendra, et al., 2001), lots of distinctions had to be made. Were students taught main idea as an objective or a strategy? Was it for fiction or non-fiction? Short, medium, or long texts? Were students presented with main ideas, choosing main ideas, identifying them, or constructing them? Were the main ideas explicit or implicit? And, if they were explicit, where in the text they appeared?

Jitendra and colleagues found that different programs taught main idea in very different ways, and none were taught it in ways very consistent with research results!

Those distinctions are important instructional considerations.

Let’s face it, it is one thing to find a main idea in a four-sentence paragraph in which the author signals its presence with language like, “The most important thing to remember…,” and it is quite another to infer an unstated main idea from a 12-page chapter on electricity.

That study didn’t even exhaust the possible distinctions. Chang & Choi (2014) showed that the inclusion of particularly interesting or seductive information in a text (like the fact that George Washington had wooden teeth or that a lightning strike once restored a blind man’s sight) can block readers from developing coherent mental representations of expository texts. In other words, interesting facts like that can distract readers from getting the main idea.

And, then there is the range of topics possible, and the amount of prior knowledge kids may have with particular topics.

To teach main idea successfully one is going to have to provide lots of practice with a rich and varied collection of texts.

The problem here is that main idea location or identification is not a really a skill, per se. Skills are highly repetitive acts, but main ideas are so varied and arise in such a wide-ranging universe of texts that repetition is only possible in artificial instructional exercises.

That’s why, despite the success researchers have often found in teaching main ideas to kids, their results usually haven’t transferred to better performance on standardized tests (e.g., Sjostrom & Hare, 1984).  Main idea teaching not only doesn’t usually lead to better general reading achievement, but doesn’t necessarily even improve kids’ performance on main idea questions (though this is because such questions don’t actually tap main idea as a separable skill (e.g., ACT, 2006; Davis, 1944)).

I’d suggest the following guidelines for teaching main idea:

1.  Since it isn’t really a skill and it doesn’t separate out from other “skills”, then teach it as part of a larger and more coherent reading strategy. The National Reading Panel (2000) found that teaching students to summarize as they read had a positive impact on reading comprehension and Graham & Hebert (2010) found that writing summaries of text was particularly powerful in the elementary grades. Summaries include main ideas of course, but these are embedded in a plethora of skills and actions.

For example, teaching summarization as a strategy means teaching students to use summarization to support their reading comprehension. They need to learn when to summarize. If I’m reading something that is difficult for me, I summarize more often—sometimes as much as every paragraph or so. In other cases, I may be able to wait until the end (or at least until the end of a section). Sometimes, I actually note these summaries down and other times it is enough to say them in my head.

In any event, the idea is that I am actively trying to understand and remember the text, by frequently stopping to retell myself the important ideas.

2.  Teach kids to summarize paragraphs first. Given all the text variations noted above, I’d start short.

I have an example of this in a Powerpoint on my site (under publications):

These slides give an example of how you would guide kids to identify the important ideas (main idea and key supporting details), deleting trivial and repetitive information, and paraphrasing the key point (main idea) in a single sentence, stated or written with the text out of sight.

Give kids lots of this kind of practice. Take any chapter in your social studies or science book and have them summarize one paragraph after another as part of their lesson. It can help to use photocopies of this text, so kids can underline, circle, and cross out information—physically separating topics, main ideas, key details, and repetitive and trivial information, or ideas that are just examples. 

3.  When kids are successful with shorter texts, teach them to try the same thing with longer texts. Either have them doing the same kind of thing with the longer text (like a section with a header in a social studies book or magazine article), or—as I would do—once they have summary statements about each of the paragraphs, see if they can come up with a summary for that collection of summaries. There is an example of that in another Powerpoint of mine, though this example is for high school students:

Or, use something like GIST (an example of that is in the first Powerpoint noted above. Students try to summarize each section of a chapter with only 20 words, and then to do the same thing for the whole chapter.

4.  Vary texts in terms of topics, difficulties, lengths, inclusion of seductive information, explicitness of main ideas, and so on. Vary the tasks so that sometimes they are writing this information down, and other times just doing it through discussion.

5.  Use “gradual release of responsibility” approaches to the use of the summarization strategy. That means model these steps for the kids, then guide them to do it themselves — with you doing less and less of the work as you go on.  

Initially you might say something like, “It helps to cross out the trivial information first. Often an author gives some examples of what he is saying, but examples are repetitive, so they shouldn’t be in a summary and we can cross them out.”

Later the teacher might say, “We need to get rid of some of the information in this paragraph so we can summarize it. What would you leave out and why?

And still later: “Now what we do?”

Eventually it should become a high success independent activity.

6.  Another useful tool is a hierarchical tree. Initially, have students read a text and give them a series of main ideas drawn from that text on index cards. The students task is to organize these cards to showing how they are connected, and then to write a GIST like summary of their organization. Some teachers like to even provide a template of the tree structure, with the students sorting the cards into the tree. Again, over time, you give less and less guidance.

Remember, the point is to energize kids to focus on meaning and to be active in their pursuit of meaning while they are reading. If they are constantly asking themselves, “what’s important here?”, “what do I need to remember?”, they will do better in reading. If they have experience doing these kinds of things in different text environments and with varying degrees of support, they’ll do better, too.


See what others have to say about this topic.

Patty Wanker
Nov 11, 2018 01:52 PM

I’m so glad that you shared your thoughts on teaching main idea. As an instructional coach I am constantly asked what is the best way to teach students MI across grades K-5 and they want consistency in our classrooms. The greatest complaint is if it’s taught each year, why don’t they appear to be getting it. It appears that it is most likely due to the fact that we can’t agree on the most effective strategies or even down to the most basic, what vocabulary to use!

Linda Perry
Nov 11, 2018 05:16 PM

Excellent information to share with colleagues. This really aligns with Nancy Hennessey's comprehension framework as well.

Sarah Tantillo
Nov 11, 2018 06:29 PM

Following up on the question "What's important here?"--you might want to check this out: I designed an organizer (cleverly called the "What's Important Organizer") and explained it here:

Sam Bommarito
Nov 11, 2018 07:20 PM

Getting ready to do an in-service next week for beginning teachers in St. Louis Public School. An overview of what you said and a link to the blog will definitely be included along with a suggestion they consider following your blog. THANKS!!! Sam

Sarah Powley
Nov 13, 2018 01:48 PM

Just last week, in my role as an instructional coach (6-12, all disciplines), I conducted a workshop I called Summary: The Single Most Important Thing You Can Do to Boost Reading Comprehension. That may have been hyperbole, but I don't think so. I am passing this post on to all who came to that workshop because you explain exactly why summary writing is so important. The message fits 6-12 as perfectly as K-5.

Jo Krajeck
Nov 13, 2018 08:50 PM

Like most literacy strategies, we, as teachers, need to offer explicit instruction, e.g., "I do it; we do it; you[student] do it." Then after explicit practice, we do many reading share-outs (anonymously) so that students are exposed to a variety of peer summaries. Eventually, my students can offer their peers revision strategies to produce the ultimate summaries. Correct practice makes "perfect"; sloppy or inconsistent practice only produces a bad habit. I agree...summary needs to become a "Habit of Mind" for all readers. Thanks for the ideas here!

Timothy Shanahan
Nov 13, 2018 09:01 PM

The research on writing summaries and the impact on comprehension and learning suggest summary writing gives a relatively bigger payoff in ethe elementary grades, whereas writing analyses and critique give more at secondary level.

Nov 14, 2018 01:57 AM

I find that when teaching expository text the focus should be on helping students understand the topic and purpose for the article. I use this approach with middle school science and social studies teachers. They have found it provides more support to students than having them identify the main idea and supporting details. I am still working on the approach but so far it is working with our on-level and struggling students.

Allie Spiva
Nov 14, 2018 03:24 AM

This is very helpful. As a K-4 reading coach, I find teachers struggle with HOW to teach MI across all grade levels.

Laura Parkhill
Nov 15, 2018 05:44 PM

Agreed! Summarizing is the best approach to ID the main idea and to repair comprehension- always teach my ELLs with the title as the main idea of a text and we start our 1-3 sentence summary with the title-

have successfully made this abstraction concrete going on 18 years for my K-5 ELLs at all proficiency levels by using the main idea glove strategy from our K-5 Scott Foresman TG in NC and now in Pearson's K-5 Reading Street TG here in TN - it's an outlined hand labeled with who/did what/where/when and why on the fingers and main idea on palm - I copied it onto a dishwashing glove so my kids could wear it when summarizing

I heard at an ESL PD that it was the idea of a George Gonzalez in ESL but I may be wrong - just want to give credit where due

Nov 15, 2018 06:29 PM

I'm so glad that I came across your site. My kid is 7 months old and I'm researching for ways to improve his brain from early ages. Also I found this amazing program

Rachel Stack
Nov 20, 2018 07:23 PM

Thanks for your point that teaching main idea, or any complex skill, successfully requires that we provide lots of practice with a rich and varied collection of texts -- and that students summarize the key knowledge as part of a coherent, frequent routine. I'd add that we must ask them to summarize each knowledge-building text in answer to compelling questions. Our students never go home excited to tell families that they learned "main idea." But after a rich study of texts to explore a question, like "How do cultural beliefs and values guide people?" they sure have main ideas, topics, and ideas -- from the text and of their own --- to excitedly share.

Joan Sedita
Dec 26, 2018 05:55 PM

Once again, you are spot on, this time about the complexity of teaching students to identify and state (in their own words) main ideas. I have been teaching (and training teachers to teach) this for 40 years to students at all grade levels, and in all subjects. It has to be taught in context with a task in mind (to take notes, to summarize, for student-generated text-based questions). I suggest this scope and sequence: (1) start with categorizing (with objects for little ones, words for students who read), (2) stated paragraph main ideas, (3) implied main ideas at the paragraph level, (4) paragraph main ideas combined to determine central idea of a passage. Explicitly teach the cognitive process for generating a main idea. I.e., compare several details (such as sentences in the same paragraph), determine what they have in common (the main idea), then generate a main ideas phrase. Also, teach the difference between a topic (much broader) and a main idea (what the paragraph or passage is saying about the topic).

Laura Nordby
Jan 24, 2019 04:11 AM

These are great suggestions. Thank you! I teach 4th Grade, and my students always struggle with main idea and summarizing, especially in expository text. I also appreciate Ida's thoughts on finding the main idea of expository text by naming the topic and purpose of the article.

What Are your thoughts?

Leave me a comment and I would like to have a discussion with you!

Comment *

How do I Teach Main Idea?


One of the world’s premier literacy educators.

He studies reading and writing across all ages and abilities. Feel free to contact him.