How Do I Teach Main Idea?

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’s 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, Dazed and Confused: The Main Idea of Main Ideas.

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 did they appear?

Jitendra and colleagues found that different programs taught main idea in very different ways, and none were taught in ways that are 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:

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.

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, Using Writing to Improve Reading (opens in a new window).

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.

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: ACT and Reading Comprehension (opens in a new window).

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.

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.

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 do we do?”

Eventually it should become a high success independent activity.

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.

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