EQ: What is the Scientific Method
Identify problem or question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion
Communicate the Results
Steps of the Scientific Method
Revamped to a Circuitous
Approach
http://mjksciteachingideas.com/pdf/STITutorial6.pdf/
PURPOSE
In this lesson, you will learn
how to use the scientific
method to create and
conduct experiments.
OBJECTIVES
1. How to write a problem
or question
2. How to construct a
hypothesis
3. How to design an
experiment
4. How to conduct an
experiment
5. How to collect data
6. How to graph data
7. How to draw
conclusions
Objective 1
Choosing a Problem/Question
Develop a question or problem
that can be solved through
experimentation.
Problem/Question
Your question must include both an
independent (manipulated) and a
dependent variable (responding).
An independent variable (or IV for short) is something
that you intentionally change in your experiment.
A dependent variable (or DV for short) is something that
changes as a result of what you intentionally changed.
Problem/Question
Examples of good questions:
 How does the amount of sunlight affect the growth of
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bread mold?
How does color influence people's food choices?
How is brand name related to the absorbency of paper
towels?
How does age affect a person's reaction time?
How do different diet supplements affect a cat's coat?
How does the size of a wheel affect the speed of a
hotwheels car?
Problem/Question
Objective 1 Quiz
How are rainbows formed?
 No Manipulated or Responding
Variable
Difficult to get materials
 Unsafe question
 Good question
Problem/Question
Objective 1 Quiz
How are rainbows formed?
No Manipulated or
Responding Variable
Problem/Question
Objective 1 Quiz
How does the type of liquid a plant
receives affect its growth?
 No Manipulated or Responding
Variable
 Difficult to get materials
 Good question
 Not a safe question
Problem/Question
Objective 1 Quiz
How does the type of liquid a plant
receives affect its growth?
Good question
Observation/Research
Make observations
and research your
topic of interest.
A hypothesis is an educated guess about the
question
To construct a hypothesis, all you really have to do is ask
yourself what you think the outcome of the experiment will
be. Use your head and research that you may have already
conducted to help you guess what the answer will be.
Formulate a Hypothesis
Begin a hypothesis with "I think that..."
Because the purpose of a hypothesis is to make a
prediction or guess about the answer to the
question, you should always start your hypothesis
out with "I think that..."
Formulate a Hypothesis
Use an "If...then..." statement
An "If...then..." statement is one that shows a cause and an
effect relationship.
Example:
“I think that if a plant is given acidic liquids, then
the plant's growth will decrease."
In this hypothesis, there is a cause (acidic liquid)
that produces an effect (decrease in plant growth).”
Formulate a Hypothesis
The hypothesis must address the manipulated
and responding variables
The cause and effect in your hypothesis are related to the independent
and dependent variables in your question.
Example:
"How does the type of music affect a plant's
growth?"
"I think that if a plant is exposed to classical music
(IV), then it will grow very fast (DV)."
Formulate a Hypothesis
Right or wrong does not matter
At the end of the experiment you will find
out whether your hypothesis was right or
not. As a scientist, you should understand
that it is not important that you "got it
right." It is more important that you learned
something about your topic. Don't get hung
up on having the right answer.
Formulate a Hypothesis
Examples of good hypotheses:
 I think that if a person reviews his or her class notes for
30 minutes each day, then his or her test scores will
improve.
 I think that if a person eats a healthy breakfast each
day, then his or her writing skills will improve.
 I think that if a plant receives light filtered through a
green piece of plastic, then it will produce more leaves.
Objective 2 Quiz: Formulating a Hypothesis
Question: How does color influence people's food
choices?
Hypothesis: I think that if people see a red sweater, then
they will choose it over a different color.
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
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"I think that..." is missing
"If...then..." statement is not included
Does not answer the question
Good hypothesis
Objective 2 Quiz: Formulating a Hypothesis
Question: How does color influence people's
food choices?
Hypothesis: I think that if people see a red
sweater, then they will choose it over a
different color.
Does not answer the question
Objective 2 Quiz: Formulating a Hypothesis
Question: How are paper towel brand names and
absorbency related?
Hypothesis: If the brand name is expensive, then the
absorbency will be higher.
 "I think that..." is missing
 "If...then..." statement is not included
 Does not answer the question
 Good hypothesis
Objective 2 Quiz: Formulating a Hypothesis
Question: How are paper towel brand names
and absorbency related?
Hypothesis: If the brand name is expensive,
then the absorbency will be higher.
"I think that..." is missing
Objective 2 Quiz: Formulating a Hypothesis
Question: How does age affect a person's reaction time?
Hypothesis: I think that if a person is older, then he or she
can react.
 "I think that..." is missing
 Does not include both the MV and the RV from the
question
 "If...then..." statement is not included
 Good hypothesis
Objective 2 Quiz: Formulating a Hypothesis
Question: How does age affect a person's reaction time?
Hypothesis: I think that if a person is older, then he or she
can react.
Does not include both the MV and the RV from the
question
Objective 2 Quiz: Formulating a Hypothesis
Question: How does the size of a wheel affect the speed of a
HotWheels car?
Hypothesis: I think that if the car has large wheels, then its
speed will be slower.
 "I think that..." is missing
 "If...then..." statement is not included
 Does not include both the MV and the RV
 Good hypothesis
Objective 2 Quiz: Formulating a Hypothesis
Question: How does the size of a wheel affect
the speed of a HotWheels car?
Hypothesis: I think that if the car has large
wheels, then its speed will be slower.
Good hypothesis
Objective 2 Quiz: Formulating a Hypothesis
Question: How do different diet supplements affect a cat's
coat?
Hypothesis: I think that using a brand-name diet
supplement will make the cat's coat very shiny.
 "If...then..." statement is not included
 "I think that..." is missing
 Does not include both the MV and the RV
 Does not answer the question
Objective 2 Quiz: Formulating a Hypothesis
Question: How do different diet supplements
affect a cat's coat?
Hypothesis: I think that using a brand-name
diet supplement will make the cat's coat very
shiny.
"If...then..." statement is not included
Objective 3
Experiment
 Develop and follow a procedure.
 Include a detailed materials list.
 The outcome must be
measurable.
Carefully decide what your controlled
variables will be
Before you do any designing, you must decide what variables
will need to be controlled or kept the same in your
experiment. Remember that you can change only one
variable intentionally - the manipulated variable.
Everything else must remain the same in your experiment
or your results will be not be valid..
Tip #2:
Decide what materials you will need to
conduct the experiment
Think about what you will be testing in your experiment and decide what
materials you will need. Write all materials down in your log book. Be sure
that the materials are ones to which you have easy access.
Once materials are listed, ask yourself how you will measure (or operationally
define) your materials and results. If you are measuring length, use
millimeters, centimeters, or meters. If you are measuring weight, use
milligrams, grams, or kilograms. To measure volume, you must use milliliters
or liters. Temperature must be measured in degrees Celsius. All
measurements must be Metric.
Tip #3:
Operationally define all variables before
experimenting
Before you begin experimenting, you must ask yourself how you will
operationally define your variables. In other words, how will you measure
them so that they can be put into number or quantitative terms?
If you are measuring growth of a plant, then how will you define "growth?" Is it
the height of the plant (measured in millimeters or centimeters)? Is it the
weight of the plant (grams)? In your experiment, does growth refer to the size
of the leaves? Whatever you want growth to be in your experiment must be
clearly defined ahead of time. Write down all measurements you will use to
define each variable operationally.
Tip #4:
List all procedures in the order in which they will be
completed
Once you decide which variables need to be controlled, what materials you will
need, and how you will operationally define your variables, you must list all
the procedures you need to complete in order to conduct the experiment.
Starting from the very beginning, list all of your procedures in order. Include
many details. Include how you will control variables. Write down how you
will measure your results.
Your finished procedures should be detailed so that anyone who wants to
duplicate your experiment can do so simply by following your list.
Example of how you should design your experiment:
1. Question: How does the amount of water affect the growth of a plant?
2. Hypothesis: I think that if a plant receives too much water, then the plant will become
unhealthy or die.
3.
Experiment design:
Controlled variables: Type of plant, age of plant, size of pot, amount of soil, type
of soil, amount of sunlight, type of water provided, time of day that growth is
measured
Materials needed: 5 small, identical plastic pots, bag of soil, bean seeds, water,
measuring cup, sunny window
Operational definitions: Water will be measured in milliliters. Plant growth will
be measured using centimeters. I will measure from the soil to tallest part of
the plant.
Example of how you should design your experiment:
Procedures:
1. Measure 300 ml of soil and pour into plastic pot. Repeat for each pot.
2. Place 3 bean seeds on the top of the soil in each pot.
3. Measure 100 ml more of soil and sprinkle over beans. Repeat for each pot.
4. Place all 5 pots in a sunny window. All pots should be positioned to receive the same
amount of light.
5. Label each pot with a number using a magic marker. Pots will be numbered 1 - 5.
6. Measure 10 ml of water and pour into pot #1. Measure 20 ml of water and pour into pot
#2. Put 30 ml in pot #3, 40 ml in pot #4, and 50 ml in pot #5.
7. Record date in log book along with water measurements for each pot.
8. Check plants at the same time every day. Measure and record height for each plant daily.
Quiz for objective 3
Question: How does color influence people's food choices?
Hypothesis: I think that if people see a red cookie, then they will
choose it over any other color of cookie offered to them.
Controlled variables: Type of cookie, color of cookies, age and
gender of people being offered cookies, size and shape of
cookies, temperature of cookies, "doneness" of cookies.
 Correct
 One of the variables listed should not be included
 More variables need to be controlled
 These are not controlled variables
Quiz for objective 3
Question: How does color influence people's food choices?
Hypothesis: I think that if people see a red cookie, then they will
choose it over any other color of cookie offered to them.
Controlled variables: Type of cookie, color of cookies, age and
gender of people being offered cookies, size and shape of
cookies, temperature of cookies, "doneness" of cookies.
 One of the variables listed should not be included
Quiz for objective 3
Question: How does color influence people's food choices?
Hypothesis: I think that if people see a red cookie, then they will
choose it over any other color of cookie offered to them.
Materials: sugar, flour, milk, butter, food coloring (blue, red,
yellow, and green), oven, cookie sheet, cookie cutter, bowls,
spoons, spatula, measuring cups, serving tray, 10 girls who are 11
- 12 years old.
 Correct
 Material list does not fit the problem or hypothesis
 Some materials listed are not necessary
 Some materials are missing
Quiz for objective 3
Question: How does color influence people's food
choices?
Hypothesis: I think that if people see a red cookie,
then they will choose it over any other color of cookie
offered to them.
Materials: sugar, flour, milk, butter, food coloring
(blue, red, yellow, and green), oven, cookie sheet,
cookie cutter, bowls, spoons, spatula, measuring
cups, serving tray, 10 girls who are 11 - 12 years old.
 Correct
Objective 4:
Conducting the Experiment
Tip #1:
Always keep variables in mind
Don't forget that the only variable that you are
changing in your experiment is the manipulated
variable. Everything else must remain exactly the
same.
Conducting the Experiment
Tip #2:
Follow your procedures
Take each step of your experiment one at a time. Stick
to the procedures that you wrote down in step 3.
Make sure you complete the procedures in exactly
the same way for each test you conduct.
Objective 5:
Collecting Data
Tip #1:
Keep raw data in your log book
Raw data is the first information you get as you make observations
during your experiment. For example, if you were charting plant
growth, you might find that on the sixth day of the experiment,
the plant has grown to a height of 1 cm. On the next day, it is 1.5
cm. Then the following day the plant is 1.7 cm. All of this
information is raw data. It needs to be kept in your log book.
Collecting Data
Tip #2:
Construct a data table to record data
easily
A data table is the easiest way you can record your information. It
looks like the diagram below. The manipulated variable is
always placed on the left side of the table, and the responding
variable is always located on the right side. When you get your
data, simply put it into the table.
Collecting Data
Tip #2 Continued:
Construct a data table to record data
easily
When you record data in a table, be sure to list the manipulated
variable numbers in the left column from smallest to largest.
Also, the numbers for the manipulated variable should fall into
a pattern (for example, by ones - 1, 2, 3, 4, 5; by fives - 5, 10, 15, 20,
25; by hundreds - 100, 200, 300, 400, 500). Look at the example
below:
Collecting Data
Tip #3:
Use a data table to help make a graph
Once you have collected your data in a table, it
will be very easy to create a graph in Step 6.
Keep all data written neatly in your log book.
Objective 6:
Graphing Data
Tip #1:
Transfer information from the data table
to your graph
Take the raw data from your data table and use the exact same numbers in your
graph. Remember that you must keep the number from the manipulated
variable side with its counterpart on the responding variable side. These two
matching numbers are called ordered pairs, and they cannot be separated from
one another. They always go together.
Objective 6:
Graphing Data
Tip #2:
Put your MV on the x axis and RV on the y
axis
The horizontal axis (or x axis) on a graph shows the manipulated variable.
Therefore, you must write your MV just below the x axis on your graph.
The vertical axis (or y axis) represents the responding variable in your
experiment. Write your RV to the left of the y axis on the graph. Look at
the graph below to see how to label each axis.
Objective 6:
Graphing Data
Tip #3:
Include operational definitions for the
MV and RV on the graph
Once you label the manipulated and responding variables on your
graph, you must also include how you will operationally define
each of these variables. For example, if you are measuring
length, you might operationally define the variable with
millimeters, meters, or kilometers. Be sure to use abbreviations
when operationally defining variables, and only use Metric
measurements.
Objective 6:
Graphing Data
Tip #4:
Use a pattern of numbers for each axis on
your graph
A pattern of numbers must be established for each axis. This pattern
must cover the smallest and largest numbers in your manipulated and
responding variables. A pattern is a series of numbers that adds an
equal amount for each successive number. Look at the examples of
number patterns below.
Pattern by ones 1, 2, 3, 4, 5...
Pattern by twos 2, 4, 6, 8, 10...
Pattern by fives 5, 10, 15, 20, 25...
Pattern by twenties
20, 40, 60, 80, 100...
Pattern by hundreds
100, 200, 300, 400, 500...
Objective 6:
Graphing Data
Tip #5:
Plot data when you finish labeling the
graph
To plot data, start with the x axis and find your first number under the MV
column on your data table. In the table below, the first number is 2.
Then, on the y axis, find the corresponding number from the RV
column on your data table. In the table below, the corresponding
number is 14. Draw one imaginary line up from the x axis and another
imaginary line to the right on the y axis until the two lines intersect.
The point of intersection is where you should plot your point. Repeat
this process for all of your ordered pairs on the data table.
Objective 6:
Graphing Data
Tip #5 continued:
.
Objective 6:
Graphing Data
Tip #5 continued:
.
Objective 6:
Graphing Data
Tip #6:
Add a title to the finished graph
The title of your graph must relate directly to your manipulated and
responding variables. It is a good idea to include both the MV and RV
in the title.
Objective 7 Quiz:
Drawing Conclusions
Tip #1:
Summarize the facts you gathered from your
experiment
Now that you have finished all the other parts of your experiment, it is
time to look at the data you have gathered. By examining the facts you
learned, you can easily relate them back to your question and
hypothesis from steps 1 and 2. Drawing a conclusion involves telling
whether your hypothesis was correct or not.
Objective 7:
Drawing Conclusions
Tip #2:
Explain how the manipulated variable
affected or changed the responding
variable
The best way to write a conclusion is to tell how your
manipulated variable influenced (if at all) your
responding variable. The point of your experiment was to
see if the MV would affect the RV. Explain what you found
out about the relationship of the MV and the RV.
Objective 7:
Drawing Conclusions
Tip #2 Continued:
Explain how the manipulated variable
affected or changed the responding
variable
Let's say your question was "How does the amount of light
that a plant receives affect its growth?" Your hypothesis
was "I think that if a plant receives a lot of light, then it
will grow more." Let's assume that this is what you found
out:
Objective 7:
Drawing Conclusions
Tip #2 Continued:
Objective 7:
Drawing Conclusions
Tip #2 Continued:
Explain how the manipulated variable
affected or changed the responding
variable
A good conclusion might be as follows:
Plants that receive too much light do not grow well. Findings indicate
that the ideal amount of light for a plant is about 12 - 14 hours per day.
In this experiment, fourteen hours of light produced the greatest
amount of growth.