Name ____________________
Period _____ Table _____ SCORE: _____/37
Understand Scientiric Method
Write A Testable Hypothesis
Use vocabulary: hypothesis, variable,
independent/manipulated variable,
dependent/responding variable,
controlled variable
Scientific research depends on observation. After making
observations, scientists try to predict what could be causing
the effects observed, and propose an explanation with a
hypothesis. The word “hypothesis” comes from the ancient
Greek word “hupothesis” meaning "to suppose" or "to put under".
When you write a hypothesis, you suppose may be happening,
and you create a way for that supposition to tested.
A hypothesis:
is a prediction statement
about the relationship between variables
and includes a measurable or testable scenario.
Here is an example of a common form for a hypothesis:
If the ________________________________________________is______________________________________,
(Independent or Manipulated Variable)
(tell how the MV is changed)
then the ____________________________________________ will _______________________________________
(Dependent or Responding Variable)
(tell how the RV will change)
because _____________________________________________________________________________________
Your Reason Why)
A good hypothesis meets these requirements:
1. It describes a condition that sets up an effect. ( IF this occurs, THEN this effect happens.)
2. It is testable.
3. It is clear and objective. Your hypothesis should be short, easy to understand, mechanically correct,
and unbiased.
4. It explains the reason for the prediction. Hypotheses explain predictions using previous observations,
research, or other background knowledge. A hypothesis is not a guess, but is an educated
statement that gives an explanation for an occurrence. Example: If “bubble wrap” is wrapped around
exposed water pipes in the winter then the pipes will be less likely to freeze than if they were wrapped in newspaper
because heat does not transfer as readily through the air in the bubble wrap.
Hypotheses and experiments use variables (any factors that can be controlled, changed, or
measured in an experiment):
The independent or manipulated variable is the one condition that you change in an experiment.
The dependent or responding variable is the variable affected by the change you created. The dependent
variable gets its name because it is the factor that is dependent on the state of the independent variable.
A controlled variable or constant variable is a variable that does not change during an experiment.
Write hypotheses that could lead to experiments for each of these ideas. (You may cross out the word “the” in your
hypotheses, if it does not fit well.)
1. Lights Out: Chlorophyll makes leaves green. What does Chlorophyll need to work? Design an experiment
where 5 leaves are covered and 1 is exposed every day, to discover if light is necessary for the chlorophyll to be in
the plant.
My hypothesis:
If the ________________________________________________is______________________________________,
(Independent or Manipulated Variable)
(tell how the MV is changed)
then the ____________________________________________ will _______________________________________
(Dependent or Responding Variable)
(tell how the RV will change)
because _____________________________________________________________________________________
2. Wilting Veggies--You have noticed that unwrapped vegetables seem to wilt more quickly in storage. Write a
hypothesis to test this observation.
My hypothesis:
If the ________________________________________________is______________________________________,
(Independent or Manipulated Variable)
(tell how the MV is changed)
then the ____________________________________________ will _______________________________________
(Dependent or Responding Variable)
(tell how the RV will change)
because _____________________________________________________________________________________
3. Cooking Water--When you put salt into simmering water, it started to boil. You want to see if adding salt to water
really does change the temperature at which it boils.
My hypothesis:
If the ________________________________________________is______________________________________,
(Independent or Manipulated Variable)
(tell how the MV is changed)
then the ____________________________________________ will _______________________________________
(Dependent or Responding Variable)
(tell how the RV will change)
because _____________________________________________________________________________________
4. Sugared Fruit—When you sprinkled sugar on your strawberries they seemed to get a lot of juice around them.
Write a hypothesis to test whether sugar pulls juice out of the berries.
My hypothesis:
If the ________________________________________________is______________________________________,
(Independent or Manipulated Variable)
(tell how the MV is changed)
then the ____________________________________________ will _______________________________________
(Dependent or Responding Variable)
(tell how the RV will change)
because _____________________________________________________________________________________
Check each of your hypotheses to see if it meets the requirements of a good hypothesis:
1. Lights Out
2. Wilting Veggies 3. Cooking Water 4. Sugared Fruit
States if/then effect
Is testable
Is clear/objective
Explains the reason for
prediction