Text Structure as a Clue to the Central Idea

Use a text's organizational pattern to shape and check your central idea statement.

The way a text is organized often tells you what kind of central idea it has. In a problem-solution text, the central idea usually names both the problem and the proposed solution. In a cause-effect text, it names what causes what. In a compare-contrast text, it states how two things are alike or different and why that matters. In a sequence or process text, it states what the process achieves.

Example: an original article first describes how a school's hallways flooded after every heavy rain, then explains how students and staff planted a rain garden that absorbed the runoff. That's problem and solution, so the central idea should include both: 'A student-planted rain garden solved the school's repeated flooding. ' If you wrote only 'The school's hallways flooded,' you would capture half the structure and miss the point.

Before writing a central idea, identify the structure with signal words such as 'because,' 'as a result,' 'in contrast,' 'first,' or 'the solution,' and make sure your sentence reflects it.

• 1Structure hints at the shape of the central idea
• 2Problem-solution ideas name both parts; cause-effect ideas name the link
• 3Check that your statement reflects the whole structure