1) Ask a question / State a Problem

2) Make observations / Gather Information

a) Deductive Reasoning: General to specific (laws, rules, principles)

b) Inductive Reasoning: Specific to General (experience & observation)

3) Form a hypothesis

4) Determine Variables:

a) Control Group: a group that does NOT receive experimental treatment

b) Independent Variable: a factor that is varied in an experiment

c) Dependent Variable: a variable that is measured in an experiment

5) Design an experiment

6) Analyze Results

7) Report your findings

Read the following excerpts of historical scientific discovery:

a) Alexander Fleming 1928

b) Beriberi – Dutch East Indies 1987

1) What was the problem in each discovery?

2) What was the hypothesis? How was it tested?

3) Was hypothesis proven correct or was it rejected?

4) Describe what type of reasoning was used in each experiment.

5) Identify the: Control Group, Independent Variable, and Dependent Variable.

I. In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture dishes. He noticed that a mold called Penicillium also growing in some of the dishes. A clear area existed around the mold. All the bacteria that had grown in this clear area had died. In the culture dishes without the mold, no clear areas were present.

Fleming hypothesized that the mold must be producing a chemical that killed the bacteria. He decided to isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth solution. This solution contained all the materials the mold needed to grow. After the mold grew, he removed it from the nutrient broth. Fleming then added the nutrient broth in which the mold had grown to a culture of bacteria. He observed that the bacteria died.

II. In 1987 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi. Those who fell ill could not eat and became paralyzed. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria.

One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens ate polished rice. Dr. Eijkman researched this interesting case. He found that polished rice lacked thiamine, a vitamin necessary for good health.