Scientific Method

What is the first step of the scientific method?

• state the problem

• form a hypothesis

• test the hypothesis

• analyze data

A student wants to test the effect of caffeine on alertness. How could we state this as a problem?

• If someone drinks caffeine, they will be more alert

• The experimental group will get caffeine

• The control group will not get caffeine

• What is the effect of caffeine on alertness?

A controlled experiment is set up to test the

• problem

• hypothesis

• data

• conclusion

What do we call the variable that the experimenter is looking to test? It is the one that causes the change in something else.

• the control group

• the experimental group

• the independent variable

• the dependent variable

In a controlled experiment, how many independent variables can the researcher test at one time?

• 1

• 2

• 3

• As many as they want

A student wants to test the effect of fertilizer on plant growth? What is the control group?

• the group that gets fertilizer

• the group that does not get fertilizer

• the fertilizer

• the growth

A student wants to test the effect of fertilizer on plant growth. Which answer describes the control group

• the fertilizer

• the growth

• the group that gets fertilizer

• the group that does not get fertilizer

A student wants to test the effect of fertilizer on plant growth. Which would be a control factor for this experiment?

• the control and experimental groups get the same amount of water

• the control and experimental groups get the same amount of sunlight

• the control and experimental groups are grown in the same temperature

• all of the above

How can a researcher increase the validity and reliability of their experiment?

• repeat it to see if the results are similar

• test a new hypothesis

• change their data

• make a new conclusion

A researcher tests the effect of fertilizer on plant growth. In order to increase the reliability of their data, the best number of plants to have in each group would be

• 1

• 10

• 100

• 1000