Not everything in science is numbers and formulas. In fact, some of the most helpful bits of information come in the form of qualitative data. Think about qualitative data as descriptions of the qualities of whatever it is you're studying.

If you're drinking a cup of hot chocolate, you might stick a thermometer in the cup and learn that the temperature of the liquid is 100 degrees Fahrenheit (you might want to hold off on drinking it, by the way, if it's that hot). You might also look at the ingredients used (chocolate, milk, marshmallows) to see what's in it. But that's not the end of the story when observing a subject, even a subject as simple as a cup of hot chocolate.

Qualitative data like sweet taste, distinctive smell, and warmth are all important observations to make. Making these observations can actually lead to a more in-depth search for particular quantitative, or numbers-driven, qualities of the subject.

Even though qualitative data is considered important in scientific research, it's also considered less valuable than numbers-heavy quantitative data. Science reports tend to carry a lot less meaning if they only stick to the subject's colors and smells.

Compare these qualitative and quantitative data: The Sahara Desert is a big place is a qualitative statement. By looking on a map (or flying over the area), you can see that the Sahara Desert is a large feature in the North African landscape. The statement is based on a quality: size. This visible quality may lead scientists to study exactly how big the Sahara Desert is. The Sahara Desert is nine million square kilometers (3.5 million square miles) is a quantitative statement. It is based on a quantity, or amount. Here, it's the amount of land in the Sahara Desert.