1. The Scientific Method

2. What is Science?
Remember, science is a process of inquiry that searches for relationships that explain and predict the physical world.
Inquiry is seeking information by questioning.

3. Inductive reasoning: Specific observations lead to general conclusion
Use Information to predict future
Deductive reasoning: General conclusions lead to making observations
Use Knowledge to eliminate incorrect answers
11/10/2018

4. Scientists use the Scientific Method
The scientific method is the process scientists use to answer questions about the natural world.
There are 6 basic steps to the scientific method
Observation
Hypothesis
Experiment
Data Collection
Analysis and Conclusion
Retest

5. Step 1: Observations Gather new information by using your senses
(sight, touch, smell, sound, sometimes taste)
An example of an observation might be noticing that students who study their notes seem to be making better test grades.

6. Step 2: Hypothesis A suggested solution to the problem or observation.
Must be testable!
Sometimes written as If…Then… statements
An example of a hypothesis is “If students study their notes, then they will make better test grades.”

7. Step 3: Experiment A “valid” experiment will:
A procedure to test the hypothesis and investigate the relationship between the independent and dependent variables
A “valid” experiment will:
Test ONE manipulated variable – You know the results are due to this one change
Have multiple trials & repeated testing – more reliable

8. A Little More about the Experiment…
Constants – factors kept the same so they will not affect outcome.
Control groups – test groups that are NOT being tested/used for COMPARISON

9. A Little Something about Variables…
The factor that is changed is known as the independent variable.
Sometimes the independent variable is known as the manipulated variable
Graphed on the x-axis
The factor that is measured or observed is called the dependent variable.
Sometimes the dependent variable is known as the responding variable
Graphed in the y-axis

10. Examples of Constants and Variables
For example, suppose you want to figure out the fastest route to walk home from school.
You will try several different routes and time how long it takes you to get home by each one.
Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

11. What are your variables in the experiment?
Varying the route is the independent variable
This is what the experimenter is changing
The time it takes is the dependent variable
This is what changes/is being measured as a result of what the experimenter has done
Keeping the same walker/pace throughout the experiment makes the walker a constant.

12. Step 4: Data Collection The data are the results of the experiment
May be quantitative (numbers) or qualitative (descriptions)
Analyze this data by creating:
charts, tables, or graphs

13. Step 5: Conclusion Either verifies or refutes the hypothesis
Verify = hypothesis was supported
Refute = hypothesis was not supported-start again
IMPORTANT: the conclusion does not try to PROVE the hypothesis right or wrong. It discusses the results.

14. It verifies the results making them more reliable
Step 6: The Retest
It verifies the results making them more reliable

15. One More Thing…
After a hypothesis has been supported over and over and over again it can become a scientific theory and even eventually a scientific law
Scientific Theory: results from continual verification and refinement of hypothesis
Explanation of a natural phenomenon
Supported by large body of scientific evidence
Obtained from many different investigations and observations
Can not be proven, only disproved and supported
Scientific Law: achieved after a scientific theory has been supported multiple times.
Describes things but does not try to explain them
Concise statement describing natural phenomenon

17. Redi’s Experiment Uncovered jars Covered jars Maggots appear
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
PROCEDURE
Controlled Variables:
jars, type of meat,
location, temperature,
time
Manipulated Variables:
gauze covering that
keeps flies away from
meat
Uncovered jars
Covered jars
Several
days pass
Maggots appear
No maggots appear
Responding Variable:
whether maggots
appear
CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.