Purposes of Text Features

Diagrams, captions, maps, and bold words each have a specific job.

Text features aren't decoration. Authors include them to help readers understand. Each one has a typical purpose. Headings organize information and tell what a section is about. Bold words highlight important vocabulary, usually defined nearby or in a glossary. Captions explain what a photo or illustration shows. Diagrams show the parts of something or how it works.

Maps show where something is located. Timelines show when events happened in order. Charts and graphs compare numbers at a glance. For example, an article about the water cycle might include a diagram with arrows showing evaporation, condensation, and precipitation. Its purpose is to show the cycle as a loop, which is clearer as a picture than as a paragraph.

When you see a feature, ask: 'What does this help me understand that the words alone might not? '

• 1Text features help readers understand.
• 2Diagrams show parts or processes; maps show locations.
• 3Ask what the feature adds beyond the words.