Aim: How can we plan a scientific investigation?

Do Now: Make a list of what you would need to find out whether a fertilizer can

affect the growth of a plant.

*Reminder*Steps of the Scientific Method

1. Make observations.

2. Ask a question based on the observations.

3. Collect background information.

4. Create a hypothesis (an educated guess).

5. Develop an experiment.

6. Collect and analyze data.

7. Form a conclusion.

8. Repeat.

How do we design an experiment?Decide what you will do to test your hypothesis.

Your experiment should include:

a. A control group (a group of subjects that are not being tested).

Example:

b. A variable group (a group of subjects that are being tested).

Example:

How do we design an experiment?

c. An Independent variable (the part of the experiment that is being tested).

Example:

d. A dependent variable (the part of the experiment that is going to be measured).

Example:

How do we design an experiment?

e. the steps you are going to take to perform your experiment.

Example:

How do we design an experiment?

f. A way to organize the data you collect. This is usually a chart, table, or graph (we will discuss further at another time).

How do we design an experiment?

g. A way to analyze the data to decide if it supports the hypothesis.

Example:

Activity • Pick one of the following scientific questions. Work

with a partner to design a controlled experiment that will help you answer the question. Write your answer on a separate sheet of paper.

1.How does salt affect the time it takes an ice cube to freeze?

2.Does the color of a container affect the rate at which the water changes temperature when it is placed in sunlight?

3.How is heart rate affected by exercise?

4.Does cold water freeze faster than hot water?

Homework #

• Begin to think about a question you would like to answer by performing a controlled experiment. Write your question down for approval by your teacher.