Course Outline 

Scientific Method  

When you are learning material--in school, from books, on TV, on the computer, from other people, politicians or special interest groups, or almost anywhere--you may wonder how they know. In fact, a very good question to ask is, "How do you know?" You may find that people often say "I read it in a book" or "I heard it on the radio" and the question becomes "How do they know?"

Science is a process of gathering data, making inferences, and drawing conclusions. It is very difficult to prove an experiment is right, but one good experiment to the contrary can prove it wrong. Much of science has been proved by what is called 'a preponderance of evidence' in a court of law. In other words, so many experiments have been done on the subject, and all point in the same direction. Thus it seems likely that a true explanation has been found. The Big Bang, Evolution, Global Warming, and Plate Tectonics are all examples of theories that are considered true because of the preponderance of evidence.

However, how much evidence is enough evidence? This is a problem you will need to grapple with soon, when you design your own experiment, and throughout life. If I do an experiment once and I get a result, is that enough to make valid conclusions? What if I do it 10 times? 100 times? When you hear politicians and scientists talk about Global Warming, some say there is enough evidence and others say there isn't. How can you know who to believe?

I wrote a masters thesis on micropaleontology. This is the study of microorganisms. Mine happened to be from the oceans. If micropaleontologists want to get an accurate idea of what organisms are found in a sample, they look at the sample under the microscope and they count how many different species they find. But how many do they have to count to get a good idea? What if they happen to pick an area that has a clump of one species. If I asked you to take a walk in the woods and tell me what kind of trees there are, how far would you have to walk find all the different kinds of trees? What if you looked around and saw only one tree, does that mean that the forest is made of only one kind of tree? In micropaleontology, it was considered that if you counted 301 fossils from one sample you would generate a statistically accurate count.

There comes a point in most fields that most of the professionals agree that enough data has been collected to create good results. The number needed will vary. As a member of society, you need to be aware of this and you need to ask the critical question when people tell you that something is happening. How do you know?!

Assignment:
Watch the Oregon Field Guide Video "Coastal Erosion"

Coastal Erosion Scientists are concerned over evidence that sand is actually disappearing from the Oregon and Washington coastlines.

Pay attention to what is happening, the evidence for it, and the conclusions they draw. Then answer the following questions on the Coastal Erosion worksheet.

1. What is the main premise of this study
2. Name at least four sources of evidence that support the main idea of this study
3. Do you think that there is enough evidence to support the idea that the problem described is occurring on a large scale? Why or why not?
4. Based on the evidence cited in this report, would you be willing to pay extra tax money to help fix this problem?
5. How much evidence is necessary to prove this point?

Go to the Coastal Erosion Worksheet

You have completed Unit 3. Go on to Unit 4, Collections >>