Main Idea in a Compare-and-Contrast Text

Use the text's structure to find a main idea about similarities and differences.

Text structure can help you find the main idea. In a compare-and-contrast text, the author shows how two things are alike and different, and the main idea is usually a statement about that comparison. Signal words include both, similarly, however, unlike, and on the other hand. Read: 'Frogs and toads are both amphibians that start life as tadpoles.

However, frogs usually have smooth, wet skin and long legs for jumping, while toads have bumpy, dry skin and shorter legs for walking. Frogs tend to stay near water, but toads can live in drier places. ' The main idea isn't just 'frogs' or 'toads'. It's 'Frogs and toads are related, but they differ in skin, legs, and habitat.

' A strong compare-and-contrast main idea names both subjects and the comparison.

• 1Compare-and-contrast texts show likenesses and differences.
• 2Signal words: both, however, unlike, while.
• 3The main idea names both subjects and the comparison.