The Scientific
Method
A Way to Solve a
Problem
What is the Scientific
Method?
• It is the steps someone takes to
identify a question, develop a
hypothesis, design and carry out
steps or procedures to test the
hypothesis, and document
observations and findings to share
with someone else.
TYPES OF OBSERVATIONS
Quantitative- involves numbers
Gravity- 9.8m/sec/sec
Qualitative- physical or chemical qualities
Observations lead to the development of a
question.
Hmmm…do ALL objects fall at this rate?
The question leads one to…
gather information
(you find out that gravity is dependent on mass of
the object and the distance that separates the
two)
and
form a hypothesis
(IF objects have a lot of mass, THEN they should fall faster)
The next step scientists take is to
create and conduct an experiment to
test their hypothesis.
( Bowling ball vs. marble drop)
Controls- height, methodology
Independent variable- what the
experimenter manipulates (changes)…
(mass of objects)
Dependent variable-What the
experimenter is measuring
(Time it takes to reach ground)
RESULTS, ANALYSIS, and
CONCLUSION:
• Finally you gather information based
on your experiment, analyze the data
to determine what your experiment
showed you about the phenomena you
questioned, and come up with a
conclusion based on it. Was your
hypothesis correct? Incorrect?
Why? What other questions does it
leave you with?
(You happen to find that both objects hit the ground at the same time!
Why????)…a lesson in perspective. The Earth was way compared to
either bowling ball or marble…it didn’t produce enough change to
measure.
The steps of the
Scientific Method are:
• Observations lead to Questions
• Background Research-what do we
already know
• Hypothesis- what do we expect
will occur
• Conduct ExperimentProcedures/Method
• Collect and Analyze
Results/Table/stats/graphs
• Conclusion
PERSPECTIVE CHANGES
EVERYTHING
• IS SCIENCE OBJECTIVE OR
SUBJECTIVE???
A lesson in perspective:
What we see is dependent on our gaze
A lesson in perspective:
What we see is dependent on our frame
of mind
What we see is
dependent on…
Angle
WHAT WE SEE IS
DEPENDENT
• …ON HOW CLOSE WE LOOK…
- BIG WORLD PPT.
CONCLUSIONS ARE NEVER
OBJECTIVE…ALWAYS SUBJECTIVE
Scientific Theories and Laws
•
Scientific theory- explanation that has been tested by repeated
experiments
Theories must explain observations simply and clearly
(theory that heat is the energy of particles in motion explains how
the far end of a metal tube gets hot when placed in an open flame)
Experiments must illustrate theory is repeatable
( the far end of the tube ALWAYS gets hot regardless of how many
times it is done)
You must be able to make predictions based on it.
( you might predict that anything that makes particles move faster
will make the object hotter. Sawing a piece of wood will make the
particles move faster, and will make it hotter as well.)
Scientific law states a repeated observation of nature but doesn’t
explain why warm objects become cooler.
Math and models
• Equations describes relationships
between quantitative measurements
• It is a universal language.
Universal law of gravitation
MODELS
• Represent things that are either too
large, small, or complex to study
easily. Also to as a mental picture to
predict what will happen (eg.
Chemical equations)
• Computer models-often mathematical
models that can save time and $$
because calculations are done by
machines (eg. Crash test for
motion/forces to improve car design)
SI units: The International System
of Units
• WHY SI??? To be on the same
page…comparing apples to apples
(meters to meters, liters to liters)
Units are just like numbers…they can
be multiplied, divided, and reduced!
• SI prefixes are for very large or
very small measurements…instead of
expressing that you traveled
800,000 m in distance, you would use
800 km to avoid using several zeros.
• SI prefixes are in multiples of 10.
• This makes it easy to convert SI
units into larger or smaller units by
moving the decimal.
Conversions
• If a person’s height is 1.85 m, how
many cm is this person?
• 1.85 m x 100 cm = 185 cm
------------m
DOES THIS MAKE SENSE???