Transcript Scientific Method

Chapter 1B
The Scientific
Method
The Scientific Method
A logical
procedure for
choosing an
answer to a
question
Using the Scientific
Method
• Define the problem.
• Do preliminary research.
• Form a hypothesis.
A Hypothesis
An educated
guess that
attempts to
answer a
problem
Example 1
THE PROBLEM
A salamander escapes from
an aquarium and is found the
next day very dried out and
dead. The next day a baby
alligator escapes and is found
a day later in good shape.
Example 1
POSSIBLE HYPOTHESIS
Although both alligators
and salamanders are
aquatic, alligators can
survive on land longer
than salamanders.
Example 2
THE PROBLEM
Two jars of home-canned
beans are placed on a shelf.
Both were canned at the same
time. After a month, one jar is
still good. The other jar is
discolored and smells bad.
Example 2
POSSIBLE HYPOTHESIS
If jars are not sealed
properly, bacteria will
destroy food.
Steps of the Scientific
Method
1. Set up an
experiment
or survey.
Steps of the Scientific
Method
2. Observe the
experiment
or survey.
Steps of the Scientific
Method
3. Collect the
information
and record it.
Steps of the Scientific
Method
4. Classify the
data.
Data
The recorded
information from
an experiment or
survey
Steps of the Scientific
Method
5. Analyze the
data.
Steps of the Scientific
Method
6. Choose the
best answer.
Steps of the Scientific
Method
7. Verify the
answer.
Steps of the Scientific
Method
8. Predict future
results.
Workability
The ability to
apply scientific
knowledge to
similar situations
Controlled Experiments
• Two groups with the
difference being one
variable
–Control group = constant
–Experimental group =
exposed to the variable
Controlled Experiments
–Independent variable = the
factor being tested; the
difference between the
control and experimental
groups
–Dependent variable = the
factor being measured;
influenced by the independent
variable
Controlled Experiments
• Only the experimental
group is exposed to the
independent variable.
• Multiple variables cause an
experiment to be invalid.
Sample Experiment 1
Problem: Does fertilizer with
insecticide help my lawn grow
faster than fertilizer without
insecticide?
Hypothesis: Fertilizer with
insecticide will make my lawn
grow faster.
Sample Experiment 1
Procedure: On one side of
lawn, put just fertilizer. On
other side, put fertilizer with
insecticide. Keep all other
factors equal. Measure and
record growth.
Sample Experiment 1
What is the independent
variable?
insecticide
Sample Experiment 1
What is the dependent
variable?
growth of the lawn
Sample Experiment 1
Which side of the lawn is
the experimental group?
the side with insecticide
Sample Experiment 1
Which side of the lawn is
the control group?
the side without insecticide
Sample Experiment 1
What variables do you
need to control?
type of fertilizer, amount of
water, amount of sunlight,
etc.
Sample Experiment 2
Problem: Does giving mice
extra vitamin B help them
grow?
Hypothesis: Giving mice
extra vitamin B will cause
them to grow faster.
Sample Experiment 2
Procedure: Give both groups of
mice the same food. In one
groups’ food, place 10 mg of
vitamin B. Do this every day for
a month. Keep all other factors
equal. Measure and record
growth.
Sample Experiment 2
What is the independent
variable?
1.
2.
3.
4.
Food
Growth of the mice
Vitamin B
There is no independent
variable in this
experiment.
Sample Experiment 2
What is the dependent
variable?
1.
2.
3.
4.
5.
Food
Growth of the mice
Lifespan of the mice
Vitamin B
There is no dependent
variable in the experiment.
Sample Experiment 2
Which group is the
experimental group?
1. The group that received
vitamin B
2. The group that did not
receive vitamin B
3. Both groups were
experimental groups.
Sample Experiment 2
Are there any variables to
control in this experiment
besides the amount of
vitamin B given to the
mice?
1. Yes
2. No
Limitations of Science
• Must deal with observable,
measurable phenomena
–Cannot deal with matters of
faith
• Can only describe, not
explain
–Cannot answer the question
“why”
Limitations of Science
• Observations may be
inaccurate.
• Observations and
interpretations are subject to
bias.
–Bias is what a person wants to
believe.
Limitations of Science
• Impossible to limit
completely the variables
• Results must be repeatable
to be considered valid.
Limitations of Science
• Cannot make value
judgments or moral
decisions
• Cannot prove or disprove
universal statements
• Cannot establish truth
Science & The Christian
• We have the
responsibility to be wise
stewards over God’s
creation.
–To “subdue” does not
mean to “destroy.”
Genesis 1:28
And God blessed them,
and God said unto them,
Be fruitful, and multiply,
and replenish the earth,
and subdue it:
Genesis 1:28
and have dominion over
the fish of the sea, and
over the fowl of the air,
and over every living
thing that moveth upon
the earth.
Science & The Christian
• Science is not in itself
good or bad.
–Science can supply
answers to some physical
problems.
–How man uses science
can be good or bad.
Science & The Christian
• Science cannot replace
faith in God.
–Science is not the answer
to man’s ultimate
problem.
Science & The Christian
A Christian should look
on science as an
opportunity given to him
by God to learn as much
as he can about God’s
creation.
Steps of the
Scientific Method
1. Set up an experiment
or survey.
2. Observe the experiment
or survey.
3. Collect & record the
data.
Steps of the
Scientific Method
4. Classify the data.
5. Analyze the data.
6. Choose the answer.
Steps of the
Scientific Method
7. Verify the answer.
8. Predict future results.