Name: _________________________________________________ Date: ___________
Period:
1
2
3
4
5
6
Writing a Hypothesis Practice
There are three parts to a hypothesis: the manipulated variable, the responding variable, and
the scientific reasoning.
Scientific Word(s)
Manipulated Variable
Responding Variable
Scientific Reasoning
Every-day Word(s)
1. When scientists design an experiment, the first step they take is to ask a research
question.
Example: Does the color of fish food affect how much food the fish will eat?
2. Then, scientists figure out how to set up their experiment by identifying their variables.
Example: Does the color of fish food affect how much food the fish will eat?
Manipulated: What can the researcher change? ______________________________
Responding: What reacts (or responds) to that change? _________________________
3. Finally scientists put the variables into their hypothesis using the If… then… because…
format.

Remember, yesterday we learned that this format is used like this:
If (what the researcher can change) then (a predicted response to the change) because
(scientific reasoning).

So, using variables, the hypothesis format looks like this:
If ________________________________ then ___________________________
because _____________________________________________
Example: Does the color of fish food affect how much food the fish will eat?
Hypothesis: If ___________________________, then _______________________
Because ____________________________________________________________
Questions 1 through 5 ask a research questions. For each question:

Underline the manipulated and responding variable in separate colors

Write out both variables

Write a hypothesis
1. How do high temperatures effect the growth of radishes?
Manipulated variable: (what the researcher can change) _____________________________
Responding variable: (a predicted response to the change) ____________________________
Hypothesis: If (what the researcher can change) __________________________________
then (a predicted response to the change) _____________________________________
because (scientific reason) ________________________________________________
_____________________________________________________________________
_____________________________________________________________________
2. Does studying while listening to music have any effect on student test scores?
Manipulated variable: (what the researcher can change) _____________________________
Responding variable: (a predicted response to the change) ____________________________
Hypothesis: If (manipulated variable) ___________________________________________
then (responding variable) _________________________________________________
because (scientific reason) ________________________________________________
_____________________________________________________________________
_____________________________________________________________________
3. Does the color of mashed potatoes have any effect on how many children will eat them?
Manipulated variable: _______________________________________________________
Responding variable: ________________________________________________________
Hypothesis: If (manipulated variable) ___________________________________________
then (responding variable) _________________________________________________
because (scientific reason) ________________________________________________
_____________________________________________________________________
_____________________________________________________________________
4. What effect does light have on plant growth?
Manipulated variable: _______________________________________________________
Responding variable: ________________________________________________________
Hypothesis: If ____________________________________________________________
then _________________________________________________________________
because ______________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
5. What effect does smiling have on teacher giving homework?
Manipulated variable: _____________________________________________________
Responding variable: _____________________________________________________
Hypothesis:
(3pts each) Write a problem for each of the following hypotheses. Identify the Responding and
Manipulated variable for each.
6. If plants are watered, then growth height will increase.
Manipulated variable:
Responding variable:
Hypothesis:
7. If chocolate is given to teachers, then amount of homework will decrease.
Manipulated variable:
Responding variable:
Hypothesis:
8. If trees have leaves, then bird nests will increase.
Manipulated variable:
Responding variable:
Hypothesis:
9. If acid rain is in water, then fish population will increase.
Manipulated variable:
Responding variable:
Hypothesis:
10. If calcium is given, then bone strength will increase.
Manipulated variable:
Responding variable:
Hypothesis: