Topic: Investigation and the Scientific Method
Transcript Topic: Investigation and the Scientific Method
Topic: Scientific Method
What is the scientific method?
Individual work (Classwork):
Write down the detailed steps to
make a peanut butter and jelly
The Scientific Method
Must be Measurable
Ideas about results
The Scientific Method
Observation/ State the Question or Problem
Hypothesis - Educated idea
Experiment – Repeatable test
Results - Measurable Data – Number/ Countable
Conclusion - Ideas about the results, comparison
Accept or Adjust Hypothesis
Some lab people will say this step is to
State the Problem, but that is because they
have already observed the way it should
Newton – apple on head?
Galileo – wandering stars
an Educated Idea (or prediction), not
guess. Guesses are random, and based on
the observations scientists have an idea
(right or wrong) about how they think
All students can achieve
Repeatable Test –. If another scientist
can’t redo your experiment or your results,
they are a miracle (religion not science).
Cold fusion (Russia)
Human cloning (North Korea)
Data– Numbers or values. Numbers by
themselves mean nothing. Numbers lie. They
can be manipulated or misinterpreted.
In the 2004 Presidential election both candidates
said they would win based on the same numbers,
and both were right and wrong. One won the
popular vote, the other the Presidency.
How did the results work based on the
hypothesis. Did we support or disprove our
One of the most common mistakes is to draw a
conclusion that has nothing to do with your
hypothesis- for example to talk about desert
animals after doing research on animals living in
Extrapolation – extending results far beyond
experiment, talking about the Nile, after
researching the Colorado
Hypothesis - Educated Idea If your conclusion is that your
hypothesis is supported you may have discovered an idea that shows how
nature works. If it can be expanded to fit all of the ideas in that category
(say physics or chemistry or biology) than it has a specific name.
Theory - Cumulative Evidence of corrected
hypotheses A theory is one of the most misused words in the
American English vocabulary. In science it is very specific- A large idea
SUPPORTED by many experiments, that is true almost all of the time
(99%). Theories have some flaw, like being unable to show how the
original cell developed (Cell theory).
Law - Happens every time
IF a theory were true all the time in
science it would be the ultimate idea- a LAW.
A LAW, like gravity, is always true. If it is disproved then it must be
reworked to account for the change. Even Einstein’s ideas underwent
changes as we discovered new things.
Things I DO NOT say in my class (except sarcastically)
THE TRUTH. NO such thing in science. Everything is up to question
as long as done in the proper way-using the SCIENTIFIC METHOD.
Just saying you don’t believe it is not enough. You have to disprove it in
a repeatable way.
PROOF. The other forbidden word. A real scientist would not use this
word at a scientific convention. We have evidence, support,
confirmation, verification, data, substantiation or indications that this is
how nature works but never PROOF.
DO all scientists use the same
• Each has a unique perspective, but generally
the same formula
• Visit my website and look up two different
sites, and compare and contrast their
Individual work (Classwork): Write down the detailed steps to
make a peanut butter and jelly sandwich
a reasonable answer
to the question
result agrees with hypothesis
result does not
If the result
1. Suffer either smallpox or cowpox once
in a lifetime 2. Milk maids who had
suffered from cowpox never had smallpox
Why do milk maids suffer from
cowpox never suffer smallpox?
A patient after recovering from
cowpox will become resistant to
both cowpox & smallpox germs