Date: September 9, 2015Aim #4: What is a controlled experiment?

HW:1) Complete SpongeBob Worksheet (due

tomorrow)2) HW #2-Textbook Guided Reading

Worksheet due Wednesday 9/163) Quiz - Scientific Method Thursday 9/17

Do Now: Warm-Up Notebook

Date Title of Activity Page #9/9 The Scientific Method10

By utilizing the steps of the

Scientific Method

How do scientists solve problems?

Our Problem:

How does our heart rate change after exercise?

Our Observations:

Our observations from prior experience tell us that heart rate tends to increase after we exercise.

Our Research:

Library

Scientific Journals

Internet Sources

Our Hypothesis:

If a person does 30 Jumping Jacks, then his/her heart rate will increase.

Our Controlled Experiment:

Remember, an experiment is done to determine the validity of our hypothesis.

We are going to design an experiment that will allow us to measure heart rate after we exercise.

Procedure:

1) Half the students will measure their heart rate for 1 minuteduring rest and write it on a piece of paper.

2) Half the students will be instructed to complete 30 Jumping Jacks.

3) Those students who completed the Jumping Jacks will measure their heart rate for one minute and write it on a piece of paper.

Sample size?

The bigger the sample size, the better the results or conclusion will be.

How many people should we use?

The number of “things” included in group.

VS

Controlled experiment

• Control group:

• Gets normal treatment.

• Experimental group:

• Gets the substance or the treatment you are testing.

In our Exercise Experiment, which is the control group and which is the experimental group?

Constant

Both groups should be treated exactly the same except for

the variable.

What are the constants in this experiment?

Variables• Definition: factors that can change

1. Independent (manipulated) – what the scientist controls or changes. (Exercise)

2. Dependent (responding) – the variable that is observed and that changes because of the independent variable. (Heart Rate)

3. Controlled variable – variables that are the same in each group. (Ex. Age, Exercise Type, Time of Day, etc…)

Identify the Dependent and Independent Variable:

1) In an experiment studying the effect of sleep on student achievement.

2) In an experiment studying the effect of caffeine on worker performance.

3) In an experiment studying plant growth in different colors of light.