The Scientific Method
A REVIEW
Controlled Experiments
Controlled experiments are necessary to
make sure that an experiment can be
repeated by another scientist.
All variables are controlled except one so
that the scientist will be able to tell what
made the difference in their results.
Purpose
The Purpose is what you are trying to find out
with your experiment.
The purpose can be expressed as a question.
Example: How will gummy bears be affected if
they are in water for 24 hours?
Research
This step involves finding out some
information about your purpose question.
Research could include:
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Reading books, web pages or magazines
Watching documentary videos
Trial and error exploration with materials
Interviewing experts on a topic
Background Knowledge
Facts you already know about your purpose
question
Facts can come from your everyday life.
Facts can also come from previous labs or
experiments.
Facts can come from your research on the topic.
Example: I know color fades when an object is
soaked in water. Some things dissolve in water.
I know when some things are soaked in water
they get bigger.
Hypothesis
Based on background knowledge
Based on research
A hypothesis is an educated guess.
A hypothesis is:
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An “if / then / because” statement
Always made BEFORE an experiment
Something that can be measured with data or
observation
Example
The hypothesis states IF my gummy bear is
in water for 24 hours THEN it will get
bigger BECAUSE when some things are
soaked in water they get bigger.
Materials List
Must be in list form
Must identify quantity of each item
needed.
Procedure
Number and write step-by-step
instructions in complete sentences.
Clear and detailed procedure is necessary
for another scientist to be able to repeat
your experiment to check your results.
Data
Data needs to be collected in order to form
a conclusion about your hypothesis.
Data can be OBSERVATIONS
Data can be a table of NUMBERS
Analysis
Analysis can be answering some or all of the
following questions:
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What happened?
Why did the experiment go the way it did?
What did you think would happen and what actually
happened?
What could possibly have caused your results?
Why did it happen that way?
Conclusion
Restates hypothesis
Accepts or rejects the hypothesis
Explains why the hypothesis is accepted or
rejected.
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Data is including to explain why the hypothesis was
accepted or rejected. The data can be observational
or numbers/measurements.
A hypothesis can be partially accepted and
partially rejected.
Example
The hypothesis stated IF my gummy bear was in
water for 24 hours THEN it would get bigger
BECAUSE when some things are soaked in
water they get bigger.
The hypothesis was ACCEPTED because before
soaking in the water the length of the gummy
bear was 2.8 cm and after soaking in water for
24 hours the gummy bear’s length was 4.0 cm.
Real Life Application
Explains how the results can be used in the
scientist’s real life.
Explains how someone can learn from the
experiment and use the results to help them
complete tasks or understand concepts.