Central ideas in informational texts: identifying the main point a nonfiction text makes about its topic (not the topic itself and not a supporting detail), distinguishing the central idea from details and from a summary, and tracing how the writer develops and refines it across a Grade 10 ELA MCAS informational passage.

What this skill is asking

The central idea of an informational text is the main point the writer makes about the topic, and identifying it is one of the most common Grade 10 ELA MCAS reading tasks. It appears as a multiple-choice question ("which best states the central idea"), as an evidence-selection item ("click the sentence that best states the main point"), and as a two-part item (Part A names the central idea, Part B asks for the detail that develops it). The skill students lose points on is the difference between the topic (what the text is about), a supporting detail (one fact among many), and the central idea (the point all the details add up to). This page covers how to state a central idea as a full point, how to tell it apart from a detail and from a mere summary, and how to trace the way a writer develops it. The transferable skill is reading nonfiction for the claim it is building, then proving it from the text. It is the nonfiction cousin of finding a theme in a story.

Topic, detail, and central idea

The first move is to separate three things students often blur.

The test for a central idea is whether the whole passage supports it. A statement that fits only one paragraph is a section idea or a detail, not the central idea of the text. A statement that names the subject without making a point ("the article is about sleep") is the topic, not an idea. The reliable check is to read an answer choice and ask, "Does the entire passage build toward this?" If yes, it is the central idea; if it covers only part, or makes no point, it is not.

Tracing how the idea is developed

Because a central idea is built from details, the two are tested together: a two-part item asks for the idea (Part A) and the detail that develops it (Part B). The skill is reciprocal. Given the details, you infer the point; given a candidate point, you check that the details support it. A longer passage can develop more than one idea, with each section advancing the whole, so for a "central idea of the passage" question, choose the point that covers the entire text, not just one section. Distinguishing the overall idea from a section idea is a common, decisive move on the MCAS.

Working a central-idea question

Try this

Q1. What is the difference between the topic, a supporting detail, and the central idea of an informational text? [Recall]

• Cue. The topic is the subject (a word or phrase); a supporting detail is one fact or example; the central idea is the main point the whole text makes about the topic, which the details develop.

Q2. An article on volunteering gives several examples of people who felt happier after helping others and ends by citing a study linking volunteering to wellbeing. State the central idea. [Short explanation]

• Cue. Central idea: volunteering tends to improve people's wellbeing and happiness. The examples and the study are supporting details that develop that point, and on a two-part item the study would be a strong Part B.