Famous Examples of the Scientific Method

Which of the following is a potential hypothesis statement for experiment #1 (chickens and beriberi)?

• If chickens are injected with blood from beriberi patients, then the chickens will contract beriberi because the blood contains bacteria that cause the disease.

• If the chickens contract beriberi, it's because the blood contains bacteria that cause the disease.

• If the chickens contract beriberi, then chickens are injected with blood from beriberi patients because the blood contains bacteria that cause the disease.

• If bacteria in blood causes beriberi then when chickens are injected with blood from patients who have the disease, they will get sick.

What independent variable did the scientists test in experiment #1?

• Chickens

• Whether or not chickens were injected with blood from beriberi patients

• Beriberi

• Whether chickens have bacteria or not

What dependent variable did the scientists measure in experiment #1?

• Chickens

• Whether or not the chickens contracted beriberi

• Bacteria

• Whether or not chickens were injected with blood from beriberi patients

What was the control group in experiment #1?

• The chickens who were injected with blood from beriberi patients

• The chickens who were NOT injected with blood from beriberi patients

What was the experimental group in experiment #1?

• The chickens who were injected with blood from beriberi patients

• The chickens who were NOT injected with blood from beriberi patients

What conclusion might the scientists have reached if they did not use a control group in this example?

• Bacteria in the blood cause beriberi

• Injections cause beriberi

• Bacteria in the blood do NOT cause beriberi

• Chickens cause beriberi

Would this first experiment be considered a failure?

• Yes, it is a failure because the results did not support the scientists' hypothesis--they were wrong.

• No, it is not a failure because while the results did not support the scientists' hypothesis, they were able to determine that blood is NOT the cause of beriberi.

What observation did Dr. Eijkman make during the first beriberi experiment (#1) that helped him design his second experiment (#2)?

• The chickens from experiment #1 ate whole-grain rice before the experiment but ate white rice during the experiment.

• Only some of the chickens from experiment #1 were injected with blood from beriberi patients.

• Some of the chickens from experiment #1 liked to eat whole-grain rice and some of the chickens liked to eat white rice.

• Bacteria in blood caused beriberi.

What independent variable did Dr. Eijkman test in experiment #2?

• Whether chickens were fed whole-grain or white rice.

• Whether or not chickens were injected with blood from beriberi patients.

• Whether chickens liked whole-grain or white rice better.

• Chickens.

What dependent variable did Dr. Eijkman measure in experiment #2?

• Chickens

• Whether or not the chickens contracted beriberi

• Bacteria

• Whether chickens ate whole grain or white rice