Name __________________________________________
Parts of an Experiment Worksheet
Date ___________________
Fill in the missing terms:
The __________________________ or manipulative variable is the one factor that you intend to change in
an experiment. What is being tested?
The __________________________ or responding variable is what change is expected as a result of the
independent variable. What the results might be due to what we are testing
The __________________________ or constants are the variables that do not change during the
experiment to have your experiment be as valid as possible and to have a true baseline for comparison.
Read through the examples below. Write down which parts of the examples are the hypotheses,
independent, dependent and controlled variables in the experiment.
1. Mary thinks that if people eat foods high in sugar, then they are more likely to develop diabetes. Mary
designs an experiment where a group of 100 people, Group A, consisted of people that had diets high in
sugar while another group of 100 people, Group B, ate diets low in daily sugar.
Hypothesis: _________________________________________________________________________
Controls: ___________________________________________________________________________
Independent variable: _________________________________________________________________
Dependent variable: __________________________________________________________________
2. Justin believes that the decreasing temperature during the fall months is what causes the color of the
leaves to change. He sets up an experiment where he placed 10 oak tree seedlings in greenhouse set at
80 degrees and an adjourning greenhouse also had 10 oak tree seedlings and was set at 50 degrees. He
was certain to give the two sets of seedlings the same amount of light, fertilizer and water. He then
observed the color of the leaves for a total of 1 month. At the end of the month, Justin observed that ¾
of the plants in the 50 degree temperature had leafs that had changed colors and only ¼ of the plants in
the 80 degree temperature began to change colors.
Hypothesis: _________________________________________________________________________
Controls: ___________________________________________________________________________
Independent variable: _________________________________________________________________
Dependent variable: __________________________________________________________________
3. If waking a bear when it is hibernating will always result in being attacked by the bear.
Hypothesis: _________________________________________________________________________
Controls: ___________________________________________________________________________
Independent variable: _________________________________________________________________
Dependent variable: __________________________________________________________________
4. Jenna wants to know how different colors of light effect the growth of plants. She believes that plants
can survive the best in white light. She buys 5 ferns of the same species, which are all approximately the
same age and height. She places one in white light, one in blue light, one in green light, one in red light
and one in the closet. All of the ferns are planted in Miracle-Grow soil and given 20 mL of water once a
day for 2 weeks. After the two weeks, Suzie observes the plants and made measurements
Controls: ___________________________________________________________________________
Independent variable: _________________________________________________________________
Dependent variable: __________________________________________________________________
What measurements could Suzy make to determine how different colors of light affect the growth of
plants?______________________________________________________________________________
____________________________________________________________________________________
5. SpongeBob loves to garden and wants to grow lots of pink flowers for his pal Sandy. He bought a
special Flower Power fertilizer to see if will help plants produce more flowers. He plants two plants of
the same size in separate containers with the same amount of potting soil. He places one plant in a sunny
window and waters it every day with fertilized water. He places the other plant on a shelf in a closet and
waters it with plain water every other day.
Controls: ___________________________________________________________________________
Independent variable: _________________________________________________________________
Dependent variable: __________________________________________________________________
What did SpongeBob do wrong in his experiment? ______________________________________
______________________________________________________________________________