Designing a Controlled Experiment

Making Connections

NY State Lab (Part B)

1. What question will you be attempting to answer?

•Does exercise affect clothespin squeezing rate?

2. Definition of the word hypothesis:

• “A tentative statement about the expected relationship between the variables”

• What hypothesis will you be testing?– If I exercise prior to squeezing the clothespin,

then the rate of clothespin squeezing will increase.

– If I exercise prior to squeezing the clothespin, then the rate of clothespin squeezing will decrease.

3a. What is the title of your experiment?

•The effect of exercise on clothespin squeezing rate

4. Plan the design for your experiment.

a. What is the dependent variable?Clothespin squeezing rate

b. What is the independent variable?Exercising before clothespin squeezing

c. What other variables will it be important to keep constant to obtain meaningful data?

Intensity and duration of exercise, time from exercise to squeezing, etc…

4. Plan the design for your experiment.

• How many people will you test?– 3 or 4

• How many trials will you conduct for each person?– 3

• What will you have each person do?– Measure # of times they squeeze a clothespin after

resting and after exercising• What safety precautions need to be taken?– Exercise alertly and behave responsibly

5. Design your data table

• Sample… Name Trial 1 Trial 2 Trial 3 Total

Average

Resti

ng

Name Trial 1 Trial 2 Trial 3 Total

Average

Exer

cisi

ng

6. Write out the steps you will follow to conduct your experiment step-by-step.

1. Squeeze a clothespin as fast as you can for 30 seconds counting squeezes and record number.

2. Repeat step 1 for two more trials.3. Perform 30 jumping jacks.4. Repeat step 1.5. Repeat steps 3 and 4 for two more trials.6. Calculate averages for resting and exercising.