The document describes the key steps of the scientific method which are used to investigate natural occurrences or solve problems: observation, hypothesis, experiment, and conclusion. It provides examples of each step and explains important concepts like variables, controls, and how to design valid experiments.

1. The Scientific Method involves a series of
steps that are used to investigate a natural
occurrence.
SCIENTIFIC
METHOD

2. Steps in the Scientific
Method
 Observation
 Hypothesis
 Experiment
 Conclusion

3. Observations
 Gathered
through your
senses
 Identifying and
clearly defining
the problem

4. Observations
 An example of an
observation might
be noticing that
many salamanders
near a pond have
curved, not
straight, tails

5. Hypothesis
 A suggested
solution to the
problem.
 Must be testable
 Sometimes written
as If…Then…
statements
 Predicts an
outcome

6. Hypothesis
 An example of a
hypothesis might
be that the
salamanders have
curved tails due to
a pollutant in the
moist soil where
they live.

7. Experiment
 A procedure to test
the hypothesis.
 Conducting controlled
attempts to test one
or more hypotheses
 Includes recording
and analyzing results

8. Experiment
Variable –
factor in the
experiment
that is being
tested

9. Experiment
A good or
“valid”
experiment
will only have
ONE
variable!

10. CONTROLS AND
VARIABLES

11. Scientific Experiments Follow
Rules
 An
experimenter
changes one
factor and
observes or
measures what
happens.

12. The Control
Variable/Group
The experimenter makes a
special effort to keep other
factors constant so that
they will not effect the
outcome.
 Those factors are called
control/constant variables.

13. What is the Purpose of a
Control?
 Controls are NOT being
tested
 Controls are used for
COMPARISON

14. Other Variables
 The factor that is changed is
known as the independent
variable.
 The factor that is measured or
observed is called the dependent
variable.

15. Example of Controls &
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.

16. What are the Variables in
Your Experiment?
 Varying the route is the
independent variable
 The time it takes is the
dependent variable
 Keeping the same walker
throughout makes the walker a
control variable.

17. One more thing… it is best
to make several trials with
each independent variable.

18. VALID EXPERIMENTS

19. Remember: To be a Valid
Experiment:
 Two groups are required ---
the control & experimental
groups
 There should be only one
variable

20. Data
 Results of the
experiment
 May be
quantitative
(numbers) or
qualitative

21. Data
 Must be
organized
 Can be
organized into
charts,
tables, or
graphs

22. Conclusion
 The answer to the
hypothesis based on
the data obtained
from the experiment
 Formulating a
generalization about
the results, which
may accept, reject or
modify a hypothesis

23. Retest
In order to
verify the
results,
experiments
must be
retested.

24. Sample Problems
Let's say I have a problem: My car won't start. How would I use the
scientific method to solve this problem?
 Problem: My car won’t start. I want it to start.
 Hypothesis: If I put gas in my car, it will start.
 Materials: 5 gallon gas can, 5 gallons gasoline, money to buy gasoline, a
ride to the gas station
 Experiment: First, I will call my friend Bill and ask for a ride to the gas
station. I will take the five gallon gas can and fill it with five gallons of
gasoline at the pump. After paying the gas station owner for the
gasoline, I will get a ride back to my car and put the gasoline in the
tank. Once the gasoline is in the tank, I will attempt to restart the car.
 Results: The car started on the first try.
 Conclusion: When I put gas in my car, it started.

25.  Mr. Smithers believes that a special juice will increase the
productivity of workers.
 He creates two groups of 50 workers each and assigns
each group the same task (in this case, they're supposed
to staple a set of papers.)
 Group A is given the special juice to drink while they work.
Group B is not given the special juice.
 After an hour, Mr. Smithers counts how many stacks of
papers each group has made. Group A made 1,587 stacks,
Group B made 2,113 stacks.
The control group of this example is Group B, because
they are not given the special juice. They are just there
for explaining the results. The experimental group of this
example is Group A, because they are given the special
juice. This is the factor that you are experimenting on.

26. Question Independent Dependent Controlled
Variable Variables Variables
(What I (What I (What I keep
Change) Observe) the same)
Who listens to The groups The amount of Ask the
music the receiving the time that each question in
most: survey: person listens exactly the
teenagers or teenagers or same way to
to music per
their parents? parents each individual
day measured
How fast does a Time measured in hours
Height of candle • Use same
candle burn? in minutes measured in type of
centimeters at candle for
regular intervals every test
of time (for • Wind--make
example, every
sure there is
five minutes)
none

27. REVIEW

28. Solving a Problem
1) Identify a Problem
2) State Observations
about the problem
3) Form a Hypothesis about
the problem (if…then…)
4) Design an Experiment to
test the hypothesis
5) Collect Data
6) Form a Conclusion
7) Retest