Transcript Using Scientific Method

Expanding on the Scientific
Method
Laws vs. Theories
Ethics
Peer Review
Limiting the Variables
Scientific Literacy
• Having knowledge or skill in the field of
science
• To acquire this knowledge, a person must be
aware of research being done by qualified
scientists.
Law vs. Theory vs. Hypothesis
Everyday language meets its match in
science!
Hypothesis
• An educated guess
• Must be able to be tested
• Has not yet been proven or proven false
Theory
• Tested and proven to be correct beyond
reasonable doubt or is true in almost every
situation.
• Ex. Quantum Theory
Scientific Law
• Proven correct in ALL situations
• Law of Gravity
• Kepler’s Laws of Planetary Motion
What is wrong with the following
statement?
• We occasionally hear of strange behavior by
pets; some have been able to find their way
home across country. Some have sensed the
impending deaths of their owners. My
theory is that this shows ESP (extra-sensory
perception) communication between pets
and their masters.
Ethics
• Cause no harm to the living organism being
tested
• Do not change results in the process of
collecting data to make the data fit the
beliefs or hypothesis of the researcher or the
organization paying for the research
What potential ethical problems
could you perceive in this
experiment?
• A group of researchers are testing a new
cancer drug.
Peer Review
• Scientists share information by publishing
results of their studies in science journals,
by giving oral or visual presentations at
science meetings, and by using the Internet
• Before an article is published by a journal it
must be approved (usually by performing
the exact same test) by a team of scientists
who are knowledgeable in that same area of
science
Using Scientific Method
Design experiments to test
explanations for the following
puzzling facts.
How to work through this process
1. State the facts and the proposed explanation.
2. Make sure you have considered
A) are the facts accurate?
B) Is there any chance the facts are wrong—
how could we find out?
C) Is there a more logical explanation?
3. If you are satisfied with your explanation, design
the experiment to predict:
How can you make sure that you are only testing one
set of characteristics at a time? This is called
limiting the variables!
2. Look at the Facts
Make sure you have considered
A) are the facts accurate?
B) Is there any chance the
facts are wrong—how could we
find out?
C) Is there a more logical
explanation?
Limiting the Variables
• Make sure that there are no other
explanations or factors that could be
causing the result
Scenario 1: What variables need to
be limited in this experiment?
• In four of the five past Presidential
elections, the taller of the two candidates
has won. It is distressing that height is an
important qualification for the Presidency of
the United States, but we live in a society in
which superficial qualities make a
difference in our attitude towards a person.
The taller you are, the better your chance
for success.
Scenario 2—What variables need to
be limited in this experiment?
• Scientists have recently discovered bacteria
fossils in rocks supposedly originating from
Mars. These rocks show that life exists on
Mars.
Scenario 3