Scientific Method
Water vs Sprite Experiment
Steps of the scientific method
Observe: the environment
Question: Recognize there is a problem
and state it in question form
Hypothesis- take an educated guess as to
the answer
Predict what we will see if we are right or
wrong
Test the predictions
Draw a conclusion
Write the template in yr NB
Observe:
Question:
Hypothesize:
Predict:
Test/Experiment
Draw Conclusion:
Observe
X-mas trees, how do we keep them alive
longer?
Question
I wonder if that will work for simple plants
too, like a bean plant
Hypothesize
I think it will help it grow faster
Predict
If it grows faster, it will be taller than the
control , within the next 2 weeks
Test/Experiment
Get beans
Get cups
Label them:
Give sprite
Watch and measure growth- every other
day
Draw Conclusion
Either it did grow faster
 or it did not,
 or still grew at the same rate.
Which means……
What makes a hypothesis valid?
It must be able to be able to be tested
Creationism: Not considered a valid
hypothesis
Evolution: We evolved from a primate-like
ancestor.
What makes an experiment valid?
Observe: Many reports of cancer in
people who live down the valley
Question: It’s the oldest part of Belleville,
and its by the polluted Passaic River
Hypothesis: Maybe the water supply is
contaminated by river water
Predict: If this is true, I will find 10 or more
families down the valley, where someone
has cancer
Test: I sent all the families down the valley
a survey to fill out and they all sent it back
Conclusion: 10 out of 500 families there
have people in the home suffering from
Cancer, so our hypothesis is right
What’s wrong with this experiment?
Experimental vs. Control
Control: other areas of Belleville
Variables?
Type of Water, food, radon, ageold/young….
You have to keep everything the same and
test 1 thing at a time
There are 2 types of variables
 Independent variable: (manipulated variable)
stands alone
 Dependent variable: (responding variable)
responds/ follows/ is expected to follow the
independent variable
 In the Sprite vs. water…what are we
adding/controlling….
 What do we expect to change because of
that?....
Why do we need a control?
It validates the experiment…
It establishes what is normal, or what
would have happened anyway….
For comparison…
When testing medication, what is the
control?
 Placebo
 Hair re-growth pill
 Results: 10 men (5 got placebo and 5 got the
pill)
 What if 4 pill and 0 placebo re-grew hair, does it
work?
 What about if… 4 pill and 2 placebo re-grew hair
 What about if 2 placebo and 2 pill re-grew hair?
For our Sprite experiment…
How many variables should we
have?
How many variables should
stay the same? List them
What is the independent or
manipulated variable?
What is the dependent or
responding variable?
Observe:
Question:
Hypothesize:
Predict:
Test/Experiment
Draw Conclusion:
Test/Experiment
Get beansGet cups
Label them:
Give sprite
Put them aside
Watch and measure growth- every other
day
Inference/ Observation
What is the difference?
Look at the following pictures, make the
inference or observation….