1. Write and answer the following question.
 How can you prove that the world is
not flat?

3. Objectives:
1. Explain what scientific methods are.
2. Explain how scientific methods are used to
answer questions.
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
a hypothesis.
6. List methods of communicating data.

4. 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
different order.

6. Ask a Question
 Helps focus the purpose of an investigation.
 Scientists often ask a question after making
observations.
 Observation
 any use of the senses to gather information.
○ Should be accurately recorded so that scientists can
use the information in future investigations.

7. A Real-World Question
 Engineers are scientists who put scientific knowledge
to practical human use.
 Engineers create technology.
 Technology
 Application of science for practical purposes.
○ For example, engineers Czarnowski and Triantafyllou
studied the efficiency of boat propulsion systems.

8.  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
money.
 Based on their observations
 Czarnowski and Triantafyllou asked the question:
○ How can boat propulsion systems be made more
efficient?

10. Form a Hypothesis
 Once you have asked a question and made
observations, you are ready to form a
hypothesis.
 Hypothesis
 Explanation that is based on prior scientific research
or observations that can be tested.

11.  Nature Provides a Possible Answer
 Czarnowski studied penguins swimming and formed
the hypothesis:
○ A propulsion system that mimics the way a penguin
swims will be more efficient than a propulsion system
that uses propellers.
 Make Predictions
 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.

12. What is a Ratio?
 Take out your Ratio worksheet from
yesterday and compare your answers
with a partner.

13. 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
experiment.
○ Tests one variable at a time.
○ By changing only that variable, scientists can see the
results of just that one change.

14.  Testing Proteus
 Czarnowski and Triantafyllou built a model penguin
boat called Proteus to test their hypothesis.
 The engineers took Proteus into open water to
collect data.
 Data
○ Pieces of information acquired through observation or
experimentation
Day Height (cm)
Cup 1 1 0.5
Cup 2 2 1.0
Cup 3 3 1.7
Plant Growth with Sunlight

15.  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
on Proteus.

16. Draw Conclusions
 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
propeller system.
○ So, they concluded that their hypothesis was
supported.

17. Communicate Results
 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.