Notes

A previous lesson in this title introduced the scientific method. Over the next few lessons, you will learn how to use the scientific method yourself and learn how scientists know what they know.

The scientific method is based on questions about observations in the natural world. What do I see, and what is causing it? Scientists want to understand the mechanism of what they see. In the aforementioned lesson, Biff wondered why the oak trees at the park were dying. Why is really a philosophical question. How is a better scientific question.

The first step in answering questions using the scientific method is to come up with ideas about possible answers. That means to form one or more hypotheses. Forming a hypothesis requires a review of what is already known. It is the scientist's version of doing homework.

In some ways, a scientist does homework the same way you do. You probably use reference books such as a textbook or an encyclopedia or the Internet to look for information.

Sources of Information

Science Journals

Information in a textbook comes from scientists who collected data. For most scientists, the information there is old news. Scientists need to know the latest information. Remember that science is a team effort. Scientists share information so that the pieces of a puzzle can come together to form the big picture.

The latest information in science is found in science journals. These journals look like magazines, but that is where the similarity ends. Papers published in science journals have been carefully reviewed by scientists.

In a way, experts from every field of science "grade" the work of other scientists. The experiments published in science journals would not be there if they had not received a passing mark. In this way, scientists feel confident that the information they are reading is correct.

When you write papers in class, your teacher probably asks you to cite your references. A scientist would never cite a reference that had not passed this peer review process. There are probably some references your teacher will not accept either. Let's look at what a good reference for schoolwork looks like.

Scientists are also interested in who has paid the costs associated with doing research. For instance, companies that sell certain products often fund research to develop and test the products. When large profits are involved, even honest companies and scientists might sometimes become biased in their interpretation of data. After all, scientists are only human. While most scientists try to be unbiased, they are not always successful.

The federal government, through agencies like the National Institute of Health (NIH) and the National Science Foundation (NSF) funds most of the research done in the United States.

That means that taxpayers help gain knowledge through research. The government pays for research to help ensure that it will be unbiased.

The Internet is only one source of information. It is probably the easiest to use, but it can also be a source of inaccurate information. Be very careful in choosing which sites you accept as having correct information.

The same is true for educational programs on television. Television is about entertainment, and while most educational programs are accurate, there are some programs that are not. Remember that entertainment programming does not always present true or correct information.

Some educational television shows are produced by biased organizations. Biased does not always mean something bad, it simply means that the whole story might not be presented. It is important to recognize who has made such programs and for what reason. The same groups that support good web pages often support accurate educational television.

So whom do you trust for information? There are many good and accurate sources of information. Let's take a look at a few.

A good scientist is not trying to prove anything but simply trying to accurately answer questions about the natural world and remain unbiased.

Predictions and Hypotheses

A scientist proposes an explanation for an observation by developing a hypothesis. The first step in designing an experiment is to state a hypothesis and make a prediction based on that hypothesis.

Once predictions have been made, a scientist can focus on designing an experiment to test the predictions. At this point, it is time to try to prove the prediction wrong. Remember, a scientist is not trying to prove that a hypothesis is correct, a scientist is trying to show that the hypothesis might be correct.

When designing an experiment, what is really being tested is the null hypothesis. This means the hypothesis is not true. It is not necessarily the opposite of the hypothesis.

Biff concluded that he could reject the null hypothesis about the acacia.

Null hypothesis: Removing acacia from experimental plots will have no effect on loss of oaks from the plot.

Can you see why? Did you reach the same conclusion? What purpose did the treatment with both independent variables serve? Was it also a kind of control?