The Scientific Method
The Skeptical Chemist
In “The Sceptical Chymist”
(1661)
Boyle stated that scientific speculation
was worthless unless it was supported
by experimental evidence.
Robert Boyle
This principle led to the development of the scientific method.
Scientific Method
is a way to solve problems.
Do you have any problems to
solve?
• Any
big or any
small
ones?
Parts of the Scientific Method
• Identify a problem .
• Research the problem
• Make a hypothesis
(a testable prediction).
• Experiment to test
the hypothesis.
• Draw a valid conclusion.
Make observation
Scientific
Method
My car will not start
Research
Look in Books, ask neighbors, go on line
Car is out of gas
Battery is dead
Bad alternator
Bad solonoid
Develop hypothesis
If the battery is DEAD then the car
will not start because there is no
electricity
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8
A Scientific Experiment
procedure
the order of events
in an experiment;
the “recipe”
variable
any factor that
could influence
the result
Experiments must be controlled; they
must have two set-ups that must differ
by only one variable.
The conclusion must be based on the data.
Data
Observations are also called data.
There are two types of data.
qualitative data
quantitative data
descriptions;
no numbers
measurements;
must have numbers
and UNITS
Identify the Qualitative and
Quantitative Data
•Car lights dim when the battery is low
•The battery produces 12 volts dc
•The gas tank contains 5 gallons of gas
•The green apples are acidic.
•The solution contains 4 grams of sugar
•The high frequency sound damages ears
• High Brass contains at least 65% zinc
Make observation
Scientific
Method
Research
Develop
hypothesis
Test hypothesis with an experiment
Replace battery
Attempt to start the car
Revise
hypothesis
Analyze data and draw
Conclusions
Car did not start
Hypothesis
is NOT
supported
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8
Make observation
Scientific
Method
Research
If we replace the alternator then it will start
because it will convert mechanical energy
to electrical energy
Test hypothesis with an experiment
Replace the alternator
Attempt to start the car
Test hypothesis
with further
experiments
Analyze data and draw
Conclusions
Car starts
Hypothesis
IS
supported
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8
Make observation
Scientific
Method
Ask question
Develop
hypothesis
Test hypothesis
with further
experiments
Test hypothesis
with an
experiment
Revise
hypothesis
Analyze data
and draw
conclusions
Hypothesis
IS
supported
Wysession, Frank, Yancopoulos,
Physical Science Concepts in Action, 2004, page 8
Hypothesis
is NOT
supported
Develop
theory
Everyday Science
Scientific Method
Making Spaghetti Sauce
Observation
Spaghetti sauce should be red.
Hypothesis
(prediction)
If I use tomato sauce it will be
red.
Test
Heat pot of tomato sauce.
Observe result
Taste the sauce - bland.
Revise hypothesis?
If I add garlic to tomato sauce it
will not be bland
New test?
Add garlic, taste - not so bland.
Conclusion
The Final Recipe.
First
Question
What does the scientist want
to learn more about?
Then
Research
Scientific Method
Gathering of information
Next
A Review
Hypothesis
An “Educated” guess of an
answer to the question
Then
Procedure/
Method
Written and carefully
followed step-by-step
experiment designed to test
the hypothesis
Next
Data
And
Observations
Information collected during
the experiment
And
Written description of what
was noticed during the
experiment
Finally
Conclusion
Was the hypothesis correct
or incorrect?
An Apple a Day Keeps the
Doctor Away
Does and an apple a day keep
you healthy?
Hypothesis
If you eat an apple a day then you will be healthy because
apples contain vitamins that help the body fight
diseases.
Experiment
Have two very large groups of people testing. One group
eats an apple a day the other does not eat apples.
Data
Track the health of each group for an extended period.
Conclusion
An Apple a Day Keeps the
Doctor Away
From the side of your bed if aimed at his head
u
o
SCIENTIFIC METHOD
How do scientists do what they do?
Well, YOU know because you're a
scientist, too!
Observation is an important part-in fact it's the part at the very start.
For it's observation that causes you to
wonder why earthworms do what they do
and clouds form in the sky.
SCIENTIFIC METHOD
Your hypothesis is a "best guess" based
on what you know about how things
work--now you're ready to go!
Experimentation lets you test the
hypothesis you've made-to see if your best guess can make the
grade.
And because variation is found in nature
everywhere
SCIENTIFIC METHOD
repeated trials should be done, and done
with care.
And don't forget to decide what variables
you'll test.
You change the independent variables,
but not the rest.
Recording your data is very important,
too; so you can analyze the results and
others can repeat what you do
SCIENTIFIC METHOD
When you've summarized your results and
your experiment is done,
you'll have more information about nature
and you'll have had some fun.
So, now you know that the scientific
method is really cool, and that scientists
don't just measure--they RULE!
The Scientific
Attitude
“This attitude is one of
inquiry, experimentation,
honesty, and a faith that
all natural phenomena
can be explained.”
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The Scientific Method