The Scientific Method
Objective: Students will be able to
understand the steps of the scientific
method and apply them to create an
experiment.
The Scientific
Method involves a
series of steps that
are used to
investigate a
natural occurrence
(phenomena).
Observation
Create a Hypothesis
Experiment/ Test Hypothesis
Collect and Analyze Results
Conclusion
Steps of the
Scientific Method
1. Observation: Make an
observations.
Observations are gathered
through your senses
What are the 5 senses?
5 Senses
•
•
•
•
•
Vision
Hearing
Smell
Taste
Touch
Make an observation
Steps of the
Scientific Method
2. Formulate a Hypothesis:
Predict a possible answer to a
problem or question.
Hypothesis must be testable
Often written as If…Then…
statements
Example Hypothesis
• If soil temperatures rise, then plant growth
will increase.
• If you get at least 6 hours of sleep, you will
do better on tests than if you get less
sleep.
Steps of the
Scientific Method
3. Experiment: A procedure to
test the hypothesis.
A procedure is a list of step to
follow in an experiment.
Experiment must include:
1) A step-by-step procedure
2) Include a detailed materials list.
3) The outcome must be
measurable.
Are these Hypothesis
measureable?
• If soil temperatures rise, then plant growth
will increase.
• If you get at least 6 hours of sleep, you will
do better on tests than if you get less
sleep.
Steps of the
Scientific Method
4. Collect and Analyze Results:
Modify the procedure if
needed.
Confirm the results by retesting.
Include tables, graphs, and
photographs.
Steps of the
Scientific Method
5. Conclusion: Include a
statement that accepts or
rejects the hypothesis.
Make recommendations for
further study and possible
improvements to the
procedure.
Steps of the
Scientific Method
6. Communicate the Results: Be
prepared to present the
experiment to an audience.
Expect questions from the
audience.
Commonly Misused Words
Be careful how you use effect and
affect.
Effect is usually a noun and affect, a
verb.
“ The effect of sugar amounts on the
rising of bread.”
“How does sugar affect the rising of
bread?”
Let’s put our knowledge of the
Scientific Method to a realistic
example that includes some of the
terms you’ll be needing to use and
understand.
Problem/Question
John watches his
grandmother bake
bread. He ask his
grandmother what
makes the bread rise.
She explains that yeast
releases a gas as it
feeds on sugar.
Problem/Question
Yeast releases a gas as
it feeds on sugar.
John wonders if the
amount of sugar used
in the recipe will affect
the size of the bread
loaf?
Formulate a Hypothesis
He comes up with a
hypothesis.
“If more sugar is added,
then the bread will rise
higher.”
Hypothesis
The hypothesis is an educated
guess about the relationship
between the independent and
dependent variables.
Note: These variables will be
defined in the next few slides.
Independent Variable
The independent variable is a
factor that’s intentionally varied
by the experimenter.
What is the independent variable
for our hypothesis?
Independent Variable
In our experiment sugar is are
independent variable.
Dependent Variable
The dependent, or responding
variable, is the factor that may
change as a result of changes
made in the independent
variable.
What is the dependent variable
for our hypothesis?
Dependent Variable
In our experiment, the size of the
loaf of bread is the dependent
variable.
Experiment
• What is the next step
before we start our
experiment?
Google Classroom Code
n3pc83
Bellringer
Create a hypothesis and determine the
Independent and Dependent variable for the
following question.
Will a plant grow higher with more sunlight?
Bellringer
Create a hypothesis and determine the
Independent and Dependent variable for the
following question.
Will a plant grow higher with more sunlight?
Create a hypothesis and determine the
Independent and Dependent variable for the
following question.
• How does classroom temperature affect
students’ performance on a test?
Experiment
Before we start our
experiment we must
complete our
procedure and
materials list.
We also must
determine a control
group.
Control Group
In a scientific experiment, the
control is the group that we
compare our results with.
Control Group
The control group is exposed to
the same conditions as the
experimental group, except for
the variable being tested.
All experiments should have a
control group.
Control Group
Because the original recipe
used 50g. of sugar , we are
going to use that amount as our
control group.
Constants
The constants in an
experiment are all the
factors that the
experimenter attempts
to keep the same.
Example
• If soil temperatures rise, then plant
growth will increase.
-Type of soil
-Type of plant
-Amount of water
-Others?
Can you think of some
constants for this
experiment?
Constants
They might include:
-Other ingredients in recipe
-Cooking time
-Oven temperature
-Type of yeast
-Type of pan used
Trials
Trials refer to replicate
groups that are exposed
to the same conditions
in an experiment.
Trials
For our experiment, we
are going to test each
amount of sugar 3
times.
25 grams, 50 grams
(control), 100 grams,
250 grams, and 500
grams
Collect and Analyze Results
Before we preform
the experiment, we
must create a table
to keep our data in.
Size of Baked Bread (LxWxH) cm3
Length x Width x Height (Volume)
Size of Bread Loaf (cm3)
Trials
Amt. of
Sugar (g.)
25
50
Control group
100
250
500
1
2
3
Average
Size (cm3)
What do our results tell us?
Size of Bread Loaf (cm3)
Trials
Amt. of
Sugar (g.)
1
2
3
Average
Size (cm3)
25
768
744
761
758
50
1296
1188
1296
1260
100
1188
1080
1080
1116
250
672
576
588
612
500
432
504
360
432
Control group
If more sugar is added, then the
bread will rise higher.
Size of Bread Loaf (cm3)
Trials
Amt. of
Sugar (g.)
1
2
3
Average
Size (cm3)
25
768
744
761
758
50
1296
1188
1296
1260
100
1188
1080
1080
1116
250
672
576
588
612
500
432
504
360
432
Control group
Conclusion
We rejects our
hypothesis, but
decides to re-test
using sugar
amounts between
50g. and 100g.
Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of
Sugar (g.)
50
Control group
60
70
80
90
1
2
3
Average
Size (cm3)
Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of
Sugar (g.)
1
2
3
Average
Size (cm3)
50
1296
1440
1296
1344
60
1404
1296
1440
1380
70
1638
1638
1560
1612
80
1404
1296
1296
1332
90
1080
1200
972
1084
Control group
Conclusion
We find that 70g. of
sugar produces the
largest loaf.
Communicate the Results
We share our results
showing that 70g of
sugar produces the
largest loaf of
bread.