Write and answer the following question.
How can you prove that the world is
1. Explain what scientific methods are.
2. Explain how scientific methods are used to
3. Describe how a hypothesis is formed and tested.
4. Identify methods that are used to analyze data.
5. Explain how a conclusion can support or disprove
6. List methods of communicating data.
What are Scientific
Methods? The ways in which scientists answer questions
and solve problems.
○ As scientists look for answers, they often use the same
steps. But there is more than one way to use the steps.
○ Scientists may repeat some steps or do them in a
Ask a Question
Helps focus the purpose of an investigation.
Scientists often ask a question after making
any use of the senses to gather information.
○ Should be accurately recorded so that scientists can
use the information in future investigations.
A Real-World Question
Engineers are scientists who put scientific knowledge
to practical human use.
Engineers create technology.
Application of science for practical purposes.
○ For example, engineers Czarnowski and Triantafyllou
studied the efficiency of boat propulsion systems.
The Importance of Boat Efficiency
Efficiency compares the energy used to move the
boat forward with the energy supplied by the engine.
Making boats more efficient would save fuel and
Based on their observations
Czarnowski and Triantafyllou asked the question:
○ How can boat propulsion systems be made more
Form a Hypothesis
Once you have asked a question and made
observations, you are ready to form a
Explanation that is based on prior scientific research
or observations that can be tested.
Nature Provides a Possible Answer
Czarnowski studied penguins swimming and formed
○ A propulsion system that mimics the way a penguin
swims will be more efficient than a propulsion system
that uses propellers.
Before scientists test a hypothesis
○ They often make predictions that state what they think
will happen during the actual test of the hypothesis.
Make a prediction
for these images.
What is a Ratio?
Take out your Ratio worksheet from
yesterday and compare your answers
with a partner.
Test the Hypothesis
After you form a hypothesis, you must test it.
Testing helps you find out if your hypothesis is
correct or not.
Keep It Under Control
One way to test a hypothesis is to do a controlled
○ Tests one variable at a time.
○ By changing only that variable, scientists can see the
results of just that one change.
Czarnowski and Triantafyllou built a model penguin
boat called Proteus to test their hypothesis.
The engineers took Proteus into open water to
○ Pieces of information acquired through observation or
Day Height (cm)
Cup 1 1 0.5
Cup 2 2 1.0
Cup 3 3 1.7
Plant Growth with Sunlight
Analyze the results:
Once you have your data, you must analyze them to
find out whether the results support your hypothesis.
The graphs below show the analysis of the tests done
At the end of an investigation
You must draw a conclusion.
○ It can help you decide what you do next.
The Proteus Conclusion
Czarnowski and Triantafyllou found that the penguin
propulsion system was more efficient than a
○ So, they concluded that their hypothesis was
One of the most important steps in an
investigation is to communicate your results
accurately and honestly.
Communicating About Proteus
Czarnowski and Triantafyllou published their
results in academic papers.
They also displayed their project and its results
on the Internet.