Environmental Science Study Guide

Scientific Method, Principles of Science

Vocabulary

Understand and be able to apply each of these terms.

1.  Hypothesis –

2.  Theory –

3.  Pseudoscience –

4.  Observation -

5.  Independent variable –

6.  Dependent variable –

7.  Constant –

8.  Experimental group –

9.  Control group –

10.  Probability –

11.  Sample size –

12.  Bias –

Critical Thinking

Be able to read, analyze, and give complete answers to questions like these.

1.  People often confuse a hypothesis with a theory. How are they different?

2.  Why is it important for scientific studies to be published and reproducible?

3.  In class, we used astrology as an example of pseudoscience. Explain specifically why or how it does not fit the criteria of science.

4.  Contrast modeled and natural experiments. What are the benefits and drawbacks of each?

5.  Take each of the steps of the scientific method and place them in correct order: experiment, form hypothesis, publish findings, collect data, identify question, conclusion.

Read the example of Edward Jenner’s discovery of the immunization against smallpox:

A British physician named Edward Jenner noticed that dairymaids living in his hometown often contracted cowpox, a nonlethal disease instead of smallpox. Dr. Jenner suspected the exposure to cowpox was somehow granting protection against smallpox. He decided to test this by intentionally infecting a young boy with cowpox, then exposing him to smallpox. Despite 20 inoculations, the boy never came down with smallpox. Meanwhile, other children living nearby that had not been exposed to cowpox were becoming infected with smallpox. Dr. Jenner reported to the Royal Society of Medicine that exposure to cowpox had successfully granted immunity against smallpox.

6.  Identify the following parts of the scientific method as utilized by Dr. Jenner:

Observation / Problem –

Hypothesis –

Independent Variable –

Dependent Variable –

Control Group –

Experimental Group –

Conclusion –

7.  Explain, using probability, why having a large sample size in a study makes the results more trustworthy.

8.  What is the difference between a blind and double-blind experiment? Which one is more likely to minimize bias?

9.  What is the placebo effect? Give an example.

10.  If scientific fraud and bias are always detected eventually, why are they such big problems? Use an example from class, such as the MMR / Vaccine study published by Dr. Wakefield.