Scientists Say: Quantitative and Qualitative

Quantitative and Qualitative (adjectives, “KWAN-ti-tay-tiv” and “KWAL-eh-tay-tiv”)

The words “quantitative” and “qualitative” describe two kinds of data. These terms also describe research using each kind of data. Quantitative research relies on numbers and measurements. Qualitative research relies on words, images or some other way to describe things without using numbers.

The word “quantitative” comes from “quantity.” Quantity tells you how much of something you have. This kind of research uses tools to take measurements. Those measurements create data in the form of numbers and units.

The daily temperature, measured with a thermometer, is one example of quantitative data. Scientists find this type of data valuable for a few reasons. For one thing, it usually lacks human bias, or opinion. A thermometer tells you objectively how hot or cold it is, not how hot or cold it feels to someone. Number data is also easy to graph. And graphs help scientists find patterns in data. A graph may reveal temperature trends from year to year.

Quantitative data has some limitations, though. For example, it usually doesn’t explain why something occurs.

The word “qualitative” comes from “quality.” A quality is a characteristic. Qualitative research may collect data in the form of words or images. For instance, a qualitative study might ask people to describe how they feel about something. Or it may ask why they did what they did.

This approach comes with advantages. It helps answer open-ended questions. That is, questions without ready-made answers to choose from. In this way, qualitative studies can be more flexible in the types of information they gather than quantitative studies.

A qualitative approach also comes with drawbacks. This kind of research can be biased, because it relies on a person’s opinions or views.

Since quantitative and qualitative data have different strengths, scientists often use both to explore questions. This can help them get a more complete understanding of what they’re studying.

In a sentence

Scientists use qualitative and quantitative research to learn how flight might have evolved.

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