Directions: Read through each scenario and identify the independent variable,
dependent variable and the control variable. Beware NOT ALL experiments will have a
control!
1. Mark notices he has dropped calls on his cell phone when he walks into his
bedroom. His friend told him to try and wrap aluminum foil around his phone
to get better signal. Mark talks on the phone in aluminum foil and talks on the
phone 3 more times while walking into hiss bedroom. With the aluminum foil
on his phone, he only drops 1 phone call.
Independent: _______________________________________________________________
Dependent: ________________________________________________________________
Control: ___________________________________________________________________
2. Heidi is a chocolate lover and eats chocolate daily. She has a bad break-out and
her friend told her eating chocolate causes pimples. Heidi continues to eat
chocolate every day for 2 weeks and counts the number of pimples she has on
her face. The following 2 weeks she doesn’t eat any chocolate and counts the
number of pimples on her face.
Independent: _______________________________________________________________
Dependent: ________________________________________________________________
Control: ___________________________________________________________________
3. Ruthie has a pet goldfish. After several months the goldfish quits growing.
Ruthie’s mom told her the goldfish might have stopped growing because the
tank is too small. Ruthie measures the size of her goldfish in its current tank,
and then put the goldfish in a larger tank. After 2 months the goldfish is now 1
cm longer.
Independent: _______________________________________________________________
Dependent: ________________________________________________________________
Control: ___________________________________________________________________
4. Nicholas has been biting his nails since he was a kid. He wants to break the
habit so he puts bitter tasting nail polish on his left hand and leaves his right
hand without polish. After 3 days he notices on his left hand have grown but he
continued to bite his right hand nails.
Independent: _______________________________________________________________
Dependent: ________________________________________________________________
Control: ___________________________________________________________________
