The Nature of Science
Roberta Gibson

Whenever I talk to a non-scientist about science I realize that, as with other fields of endeavor, scientists have their own vocabulary and set of rules of conduct. I thought that perhaps it would be helpful to those of you who haven’t had much experience with science to cover some of the basics. Hopefully this will give you a better idea about how scientists see themselves and how science works.

What is science exactly? This is not an easy question. Before I go ahead, you should know that the first book I picked up said, “Scientists have been remarkably unsuccessful in helping nonscientists to understand science.” (1) Let’s hope the authors were wrong!

When I was teaching I often explained to my students that science is a way of seeking principles of order in our world. We all want order. Look at how many people are willing to pay extra for special license plates rather than having random numbers and letters attached to their cars. Scientists go even further. They really want to know how everything is made, how everything works, why this or that happens, and to provide explanations for the occurrence of events. If water boils, they want to know why. If a ladybug eats more aphids in the sun than shade, they want to know why.

The explanations for these events are posed as hypotheses, ideas about how something works. For example, ladybugs probably eat more aphids in the sun because they move faster when they are warm. A hypothesis must be testable; there must be a way to show that it is wrong. For example, to see if ladybugs eat better when warm, a test could be devised to warm the ladybugs in the shade.

Even though the scientist poses the hypothesis about the way something works, he or she must remain objective during the testing of that hypothesis. Very often the rejection of the hypothesis advances our knowledge by eliminating certain explanations and pointing the way to new and potentially better hypotheses that can again be tested. It is difficult and time consuming for a scientist to make sure an experiment is done as accurately as possible. If he or she doesn’t, though, then someone else will point out the mistakes when the work is reviewed for publication or even after it has been published. For example, in the news recently there was a story about how the use of nightlights in babies’ rooms had been linked to near-sightedness later in life. The authors were suggesting that we might need to remove nightlights to prevent near-sightedness. Since that report, two independent labs have shown that no such relationship exists and that in fact it may be that near-sighted parents are more likely to use nightlights. Near-sighted parents definitely are much more likely to have near-sighted offspring. I am very near-sighted and if I hadn’t had a nightlight during those first few months of parenthood, I probably would have been diapering the cat or burping a pillow.

Scientists are often better at describing the methods they use to do science than describing what it is (2). When scientists perform an experiment, they use what is called the “scientific method.” The following steps are necessary when using the scientific method:

1) State the PURPOSE - decide what question to answer.

2) The HYPOTHESIS - make a guess as to how the experiment should come out. The hypothesis has to be testable.

3) METHODS - Figure out how to test the hypothesis and then write up how it was tested.

4) A CONTROL may be necessary. This means to leave one object or unit alone to see how it would have fared without the change.

5) RESULTS - Perform the tests and record the results.

6) CONCLUSIONS - Look at the results and make conclusions.

Is that a lot of jargon? Let’s look at an example. I want to know what is the best diet for my guinea pigs. That is my purpose. My hypothesis is that if I add the fresh vegetable kale to their diet (which is rich in vitamin C), the guinea pigs will grow better. How will I show the hypothesis is wrong? I will keep some guinea pigs on a diet of just pellets. They will be the controls. Then I will feed another group pellets plus lettuce and another group pellets plus kale. I could even have a group that I fed pellets plus oranges, which have even more vitamin C. I would also have to make sure each group got the same amount of pellets. Next I have to decide what would be a good measure of growth. I decide that weight would be an easy measurement to take and would be a reliable estimate of health and growth. I wrote down exactly how I did everything. That was the method. Then I did it. I weighed each guinea pig after several weeks and took the average of each group. Those are my results. I found that the guinea pigs with kale did weigh more, even more than those given oranges. Why? Because I observed that guinea pigs didn’t like to eat oranges. Those were my conclusions.

I hope this helps you understand science a little better. For the next issue I will discuss how mathematics and science are related.

References:

1. Garvin McCain and Erwin Segal. The Game of Science, 5th Ed. Brooks/Cole Publishing Company, Pacific Grove, California. 1988.

2. Ernst Mayr. The Growth of Biological Thought, The Belknap Press of Harvard University Press, Cambridge, MA. 1982.

Copyright October 2000
Originally published in November/December 2000 issue of HELM (Home Education Learning Magazine)