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Reading strategies and how to teach them: Determining the important idea

Reading strategies and how to teach them: Determining the important idea

Ask a reader what they have learned from a text

and they might either give you a short, accurate summary of what they read, or skip past the main concept (probably to tell you about something they simply found interesting).

If they’ve answered with the latter, it’s likely that they need help with a very important reading strategy: determining the important idea. This is the strategy that teaches students to find the main idea(s) of a text, and to sort them from the parts that are just interesting details.

It’s a strategy very closely related to summarizing, and it helps readers to...

  • Distinguish what’s important from what’s interesting
  • Identify a theme, opinion or perspective
  • Remember important information
  • Learn new information
  • Answer a question (which will come in handy when they have to sit tests!)
  • Determine if the author’s purpose is to inform, persuade, or entertain

Getting to the point

Finding the main idea in a text is critical for comprehension because the important ideas are the purpose of the text. It’s what the writer is trying to tell readers.

If students can’t tell you what the main idea is, they won’t fully understand the text, or be able to infer why the author might have written it.

It’s a strategy that is particularly important when it comes to non-fiction texts. Non-fiction texts usually come with added challenges: diagrams, maps, tables, illustrations, charts, photographs with captions, specially chosen fonts, text features such as italics or bold words, glossaries, tables of contents, and bullet points. All of these things convey important ideas or have special meaning.

And while there can be a main idea per paragraph, there’s usually only one overall important idea in any given text – but sometimes what a reader chooses as an important idea can vary depending on their life experiences and perspective. 


Don’t sweat the small stuff

In reading, the ‘small stuff’ is the supporting ideas: the interesting facts, quotes, or evidence that the author uses to support the important idea in the text. These details help expand the point the author has made with the important idea – it supports their reasoning, and gives interesting background information for greater depth of understanding.

Here’s an example:

Remember, remember the 5th of November! 
The Gunpowder treason and plot 
I know of no reason 
Why the Gunpowder treason 
should ever be forgot.

The important idea: The gunpowder treason should be remembered.
The supporting details: It happened on November 5th.

Help students differentiate supporting ideas from important (main) ideas by modeling how you find important ideas and distinguish them from supporting details.

Here’s an example from a text in our CSI Literacy Aqua (Grade 4) kit:

After you read the first paragraph aloud, model how you determined the important idea. For example, “The first sentence of this paragraph summarizes the important idea: Courtney Thompson was a very good gymnast as a 10-year-old. The supporting ideas are the evidence we are given to show this: the fact that she practised a lot and that she wanted to go to the Olympics.” 

More support for determining important ideas:

  • To find the important ideas, ask “What is the author trying to say in the text?”, and follow up with, “Why is this an important idea?”
  • If students have different “important ideas”, have a discussion about their thinking and support them to appreciate different viewpoints.
  • Text features (such as diagrams, maps, tables, graphs, and captions) can also be important ideas or supporting details. Talk about whether the feature is an important idea itself, or whether it supports an important idea in the text.
  • To help students sort the important ideas from the supporting details, have students annotate the text with two different highlighters: one colour for important ideas, and another colour for supporting details.
  • As students become familiar with the strategy, use the important ideas to find the author’s writing purpose, and the main theme, moral, or message of the text overall.
  • Check out our free determining important ideas lesson and anchor chart to introduce this reading strategy to your students.


Want a strategies resource for your whole class? Try CSI Literacy Kits for mainstream classes and Enhance Literacy for intervention classes. Both resources are complete with short texts, lesson plans, collaborative learning, student reflection journals, and digital resources. Download sample texts from our resources.

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