COMPARING AND CONTRASTING

One way to understand the ideas you read about is to compare and contrast them. In everyday language, compare means to look for similarities and differences while contrast means to just look for differences. As a reading strategy, however, compare and contrast are used more specifically. When you compare two things, you discover how they are alike; when you contrast two things, you find out how they are different.

To compare things, you look for similarities...ways that people, events, things, or ideas are alike. For example, several scientists may have used the same experiments, two discoveries may have taken place at the same time, and cells may share the same basic structure.

To contrast things, you look for ways that people, events, things, or ideas differ. Textbooks like Biology: The Web of Life often use illustrations to show contrasts. For example, Figure 14.5 from your textbook contrasts a healthy leaf with one infected with a viral disease.

Notice how much smoother the leaf on the left is. Note that things can be alike in some ways and different in others. Although one of the leaves shown is healthier than the other (contrast), both are about the same in size and color (comparison).

When you read, it is often easier to find similarities first and then to look for differences. Start with comparisons and then move on to contrasts.

WHAT TO LOOK FOR

Writers often point out comparisons by using signal words and phrases that give you clues about the structure of the passage. Many times, these words and phrases appear in the beginning or middle of a sentence. Look for the words shown below.

Signal words and phrases that show similarities

similarly	like	still	likewise
in the same way	in comparison	at the same time	in the same manner

To Contrast
Look for ways that people, events, things, or ideas are different from each other. Look for internal as well as external signs. Ask yourself what makes one thing different from another.

Just as there are signal words and phrases that give you clues about comparison, so there are signal words and phrases that show contrast. Look for the words shown below.

Signal words and phrases that show contrasts

however	on the other hand	but	nevertheless	conversely
rather	on the contrary	yet	nonetheless	in contrast

TRY IT!