Forming A Hypotheses
Name: __________________________________________________________________________
Rules for writing a Hypothesis statement:
 They should be clear - This means they should be easy to read, short, and understandable. They should be written in
simple English, and should be framed as if you are writing to a layperson.
 They should be simple - This means they should be as brief as possible, while still being powerful. They should
reflect the major factors. You need to take a stand for your position, and maintain that stance.
 They should be direct - You should convey your stance as clearly as you can. Do not mix multiple hypotheses into
one long, drawn out statement. Try to keep it to as few words as possible.
 They should be measurable by your research - When you state your hypothesis, ask yourself, ‘And how would I
prove this within the course of my experiment design?
 To formulate a workable hypothesis, remember that it addresses the question, directs the experiment, and has a
measurable outcome. It should be stated as an ‘‘if, then, because’’ statement.
 ‘’If we_____(do something) ___then___(something else)____will happen, because ___(explains your reasoning)__.’’
Example Question: How does the type of light affect the growth cycle of a flower?
Hypothesis: If a pansy is placed in natural light then it will grow higher than a pansy grown in the artificial light because
natural light contains more of the energy plants need thrive.
Part I: Write a hypothesis for each of the following problem statements. In addition, identify the dependent and independent
variable for each.
1.
2.
3.
How will the number of leaves on a tree affect how many birds will build nests in it?
a. Hypothesis: If _______________________________________________________________________________________________________,
b. then __________________________________________________________________________________________________________________
c. because ______________________________________________________________________________________________________________.
d. Independent Variable: _____________________________________________________________________________________________
e. Dependent Variable: _______________________________________________________________________________________________
How does the acid level of a lake affect how many fish live there?
a. Hypothesis: If _______________________________________________________________________________________________________,
b. then __________________________________________________________________________________________________________________
c. because ______________________________________________________________________________________________________________.
d. Independent Variable: _____________________________________________________________________________________________
e. Dependent Variable: _______________________________________________________________________________________________
How does the amount of milk you drink affect the strength of your bones?
a. Hypothesis: If _______________________________________________________________________________________________________,
b. then __________________________________________________________________________________________________________________
c. because ______________________________________________________________________________________________________________.
d. Independent Variable: _____________________________________________________________________________________________
e. Dependent Variable: _______________________________________________________________________________________________
Part II: For each of the following questions, create a good hypothesis. Remember to write COMPLETE SENTENCES in IF, THEN,
BECAUSE form.
4.
5.
6.
How does the amount of chocolate you eat relate to pimples?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
How does having salt in soil affect plant growth?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
How would plant growth be affected by the color of the light?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
7.
8.
9.
c. Dependent Variable: _____________________________________________________________________________________________
How might bacterial growth be affected by temperature?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
Does ultraviolet light cause skin cancer?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
Does temperature cause leaves to change color?
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
Part III: Write the question that was most likely being answered by each of the following hypotheses. Again, identify the variables
present in an experiment to test the hypothesis.
10. If I feed my dog Purina Dog Chow, he will have more energy because Purina is full of vitamins.
a. Likely Question:__________________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________
11. If I give my teacher chocolate, then she will give me less homework because she will be happier.
a. Formal hypothesis:_______________________________________________________________________________________________
_____________________________________________________________________________________________________________________
b. Independent Variable: ___________________________________________________________________________________________
c. Dependent Variable: _____________________________________________________________________________________________