Main Idea, Purpose, & Audience

Text evaluation and analysis usually start with the core elements of that text: main idea, purpose, and audience.  An author needs to consider all three of these elements before writing, as they help determine the author’s content and language.  As a reader, it’s important to ascertain these aspects of a text which exist as a foundation for the author’s content and language.

Main Idea

Always start with the main idea.  Main ideas may be stated directly in the text or implied; you need to read a text carefully in order to determine the main idea. Put the main idea into your own words, so that it’s expressed in a way that makes sense to you.  Then ask and answer the following basic questions about that main idea:

  • Is the main idea reasonable/believable to most readers?
  • Is the main idea clear and if not, why do you think the author embedded it?
  • Is the main idea the author’s opinion, or is it something that the author asserts about an issue?

Asking and answering these questions should help you get a sense of the author’s intention in the text, and lead into considering the author’s purpose.


Main idea and purpose are intricately linked. There are a few basic purposes for texts; figuring out the basic purpose leads to more nuanced text analysis based on its purpose. Basic purposes of a text include:

  • to inform – to describe, explain, or teach something to your audience
  • to persuade/argue – to get your audience to do something, to take a particular action, or to think in a certain way
  • to entertain – to provide your audience with insight into a different reality, distraction, and/or enjoyment

The following video more fully explains these different purposes of a text, and adds a fourth, to share insights or feelings.

Main Idea & Purpose Determine Analysis

The author’s main idea and purpose in writing a text determine whether you need to analyze and evaluate the text.  They also determine the pieces of the text you should analyze—content or language or both.

If the purpose is to persuade or argue

You always need to analyze the text to see if the main idea is justified.  Do the supporting ideas relate to and develop the main idea? Is the supporting evidence taken from recognized, valid sources?  Is the author arguing via language instead of evidence or facts?  Persuasion and argument need to present logically valid information to make the reader agree intellectually (not emotionally) with the main idea.

If the purpose is to inform

You usually need to analyze the text, since the text needs to present valid information in as objective a way as possible, in order to meet its purpose of explaining concepts so a reader understands.

If the purpose is to entertain

You may or may not need to analyze the text. Writing that entertains does not necessarily have to be either logical or complete in order to accomplish its purpose. You may want to analyze the text for language, though, to see how the author manipulates language to accomplish their purpose.


Who are the author’s intended readers?  Figuring out this will help you understand an author’s approach to providing the main idea with a particular purpose. Does the audience know little or nothing about the topic, or are they already knowledgeable?  Is the audience’s knowledge at beginner or expert level, somewhere in between, or mixed? Does the audience include people who may be skeptical of the author’s ideas?  Does the audience include people who outright oppose the author’s ideas? As you can see, asking and answering questions about audience can help an author determine the type and amount of content to include in a text. As a reader, it’s important to figure out the author’s intended audience, to help you analyze the type, amount, and appropriateness of the text’s information.

The following video presents the concept of audience from a writer’s perspective, but the concepts are applicable to you as a reader who needs to consider audience as a foundation for evaluating a text.

You may also want to link to one of Purdue’s Online Writing Lab’s page on Author and Audience to get a sense of the wide array of variables that can influence an author’s purpose, and that an author may consider about an audience.

try it

Read the article “Forget Shorter Showers” by Derrick Jensen.

Note that most of the Try It exercises in this section of the text will be based on this article, so you should read carefully, annotate, take notes, and apply appropriate strategies for reading to understand a text.

Then answer the following questions about the article’s main idea, purpose, and audience.

Which selection best represents the author’s main idea?

  1. We have it in our power and right to take action to stop the industrial economy over-using and wasting our natural resources.
  2. We are victims of a campaign of misdirection, being told and accepting that our personal use of natural resources is both the cause of scarcity and the solution to preservation.
  3. Because we have accepted our identities as consumers, we reduce our forms of political existence to consuming and not consuming.
  4. Simple living is better for the planet than over-consumption.


Which selection best represents the author’s purpose?

  1. to inform readers about the actual use of resources by individuals vs. the industrial economy
  2. to persuade readers to consider taking action against an unjust situation that assigns blame to individuals instead of big business in regard to the depletion of natural resources
  3. to persuade readers to re-think their personal attempts to live more simply and more “green”
  4. to entertain readers interested in nature with accusations against the industrial economy


Who comprises the author’s audience and what cues can you use to determine that audience?