I have been making observations*

advertisement
I have noticed some things…
Using the scientific method
My observations were…
• All scientific questions and studies start here!
• I have noticed a lot of students chewing things
like gum, candy, or sunflower seeds.
Observations vs. Inference
Observations
Inferences
• Using your senses or a tool to
record an event, characteristic,
or behavior
• A logical conclusion drawn
from observations and prior
knowledge
• NO BIAS
• Example:
• Example:
Qualitative vs. Quantitative
Observations
Quantitative
Qualitative
• A measured observation
• A useful, descriptive
observation
• Example: Miss Smith is 162
cm tall.
• Example: the substance in the
flask is giving of a pungent
odor
My Problem (Question)
• Scientific questions must be able to be answered
by observations and gathering evidence
▫ questions come from observations
▫ must be testable through experimentation, survey or research
▫ Deal with the natural world
▫ Be genuine, something we don’t already know the answer to
• How many chews does it take to finish a tootsie
roll?
Some information I know..
• Gather information & do research
• They are kind of difficult to chew
• They are a little thick
My hypothesis
• A possible explanation for your problem or
questions
• Not a fact
• Must be testable
• “If…., Then…” statements
• If tootsie rolls are difficult to chew, then it will
take 50 chews to finish one tootsie roll.
My experiment
• Must have clear steps
• Must be controlled- only change 1 variable at a time
• Variable- factors that can change in an experiment
▫ Independent- the 1 factor you change
▫ Dependent- factor that may change in response to
independent variable
▫ Contstants- factors that remain the same
• Must have a control group- nothing is changed so
you can compare your results
• Count how many chews it takes to finish a tootsie
roll
Next step, Collect Data
• Tables should be created before you begin
• Facts and figures gathered through observation
and experiment
• graphs
Conclusions
• Summary of what you found
• Did my results support or refute my hypothesis?
• What’s next?!
• Need more tests!
• Why?
Do your results support your
hypothesis?
• Test again to get more support
Do your results disprove your
hypothesis?
• Re-work or re-write your hypothesis and
continue through steps from there
Theory vs. Law
• Theory – well tested, repeatable
hypothesis that attempts to
answer WHY- ACCEPTED AS
TRUE UNTIL PROVEN
OTHERWISE
***Not always true or proven.
Example: Theory of Evolution
• Law- A statement meant to
DESCRIBE an action or set of
actions
***Proven to be true ALL
the time
• Example: Newton’s 1st Law of
Motion- an object at rest stays at
rest unless acted upon by an
outside force
Sample Experiment
3. Test the Hypothesis – Example of a Test
▫ Experimental Scenario: Ms. Freeman and Ms. Dowd wanted to
determine if there was a correlation between eating a nutritionally
balanced breakfast and success on tests. One group of students
was given a healthy breakfast and another group ate their normal
breakfast before a test. They found that 7 out of 10 students who
ate the healthy breakfast scored 80% or better on tests while 5 out
of 10 students who ate their regular breakfast scored 80% or
better on tests.
▫ Identify the following from the above experimental scenario:
 Independent Variable: ___________________________________
 Dependent Variable: ____________________________________
 Controlled Variables: ____________________________________
 Control Group: ________________________________________
 Experimental Group: ____________________________________
Download