Steps of Experimental Design:
M&M Investigation
Well-Defined Questions
Ask about objects, organisms, and events
in the natural world.
Can be answered through investigations
that involve experiments, observations, or
surveys.
Are answered by collecting and analyzing
evidence that is measurable.
Relate to scientific ideas rather than
personal preference or moral values.
Do not relate to the supernatural or to nonmeasurable phenomena.
How does a paper airplane fly?
Not welldefined.
Does the shape of the wing affect how
far a paper airplane will fly?
Welldefined!
Is rock music better than hip-hop
music?
Not welldefined.
Does rock music make more money
than hip-hop music?
Welldefined!
What temperature of water will
dissolve M&Ms faster?
Welldefined!
Which M&M tastes better: red or
yellow?
Not welldefined.
Experimental Design:
M&M Investigation
HYPOTHESIS
A hypothesis is an educated guess about how
things work.
Most of the time a hypothesis is written like this: "If _____[I do this],
then _____[this]_____ will happen.“


For example: “IF a plant receives fertilizer, THEN it will grow bigger than
a plant that did not receive fertilizer.

Other ways to write a hypothesis:
- I predict that ______________ because _______________.
- I hypothesize that __________________ because______________.

Your hypothesis should be something that you can actually test.

The word HYPOTHESES is plural for hypothesis.
HYPOTHESIS
Now write your own hypothesis based on the question:
“Do some M&M colors dissolve faster in water than others?”
Write your hypothesis behind the “Hypothesis” tab
in your foldable.
Remember:
- your hypothesis needs to be in an “if”/”then” statement
- your hypothesis must be testable
Examples of Possible Hypotheses


IF the M&M has a darker color, THEN it will
dissolve faster.
IF the M&M has a lighter color, THEN it will
dissolve faster.
MATERIALS
A materials list is important in
organization and planning.

It is important to list all
materials you will need in order to
carry out the experiment.

MATERIALS
Behind the “Materials” tab in your foldable, list all of the materials that
you will be using in the M&M Investigation lab.
Materials:

White plastic plates
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Different colored M&Ms
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Water
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colored pencils
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a quarter
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Plastic cup, 3 ½ ounces
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Permanent marker
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Stopwatches
VARIABLES

Scientists use an experiment to search for cause and
effect relationships in nature. In other words, they design
an experiment so that changes to one item cause
something else to change in a predictable way.

These changing quantities are called VARIABLES.

An experiment has 3 kinds of variables:
independent (manipulated), dependent (responding) and
controlled (constants)
INDEPENDENT VARIABLE

The independent variable is the one that is purposely
changed or manipulated by the scientist. To ensure a fair test, a
good experiment has only one independent variable. As the
scientist changes the independent variable, he or she observes
the changes.
Example:
Does the amount of fertilizer affect plant growth?
The amount of fertilizer is the independent variable
because the scientist has control over how much
fertilizer is used in the experiment.
EXPERIMENTS CAN HAVE ONLY 1 INDEPENDENT VARIABLE
Suppose that you wonder whether you can run a marathon faster when
you eat pasta the night before or when you drink coffee the morning of the
race.
Your hunch is that loading up on pasta will give you the energy to run faster
the next day. The independent variable is the consumption of pasta, and the
dependent variable is how fast you run the race.
Now, if you eat several plates of spaghetti the night before you race, but then
get up the next morning and drink two cups of coffee before you head to the
start line, your experiment is useless.
Why is it useless? By drinking the coffee, you introduce a second independent
variable, so you will not know whether the faster race time is due to the
pasta or the coffee.
Experiments can have only one independent variable.
If you want to know the effect of caffeine (or extra sleep or improved training) on
your race time, you would have to design a second (or third or fourth)
experiment.
What is the
independent variable
in your M&M investigation?
Independent Variable:
M&M Color
Why is M&M color the independent variable?
DEPENDENT VARIABLE


The dependent variable is what is measured in the
experiment.
The scientist focuses their observations on the dependent
variable to see how it responds to the change made to the
independent variable.
Example:
Does the amount of fertilizer affect plant growth?
The dependent variable is plant growth.
This can be MEASURED, and it RESPONDS to the
change made to the independent variable.
(amount of fertilizer)
What is the
dependent variable
in your M&M
investigation?
Dependent Variable:
how fast the M&M
colors dissolve
Why is “the speed that the M&M colors dissolve” the dependent variable?
CONTROLLED VARIABLE
(CONSTANTS)

When conducting an experiment, all other variables must be
kept the same throughout the investigation; they should be
controlled. The variables that are not changed are called
controlled variables. (constants)
Example:
Does the amount of fertilizer affect plant growth?
Independent variable: amount of fertilizer
Dependent variable: plant growth
Controlled variables: same type of plant, same pot size,
same amount of water, same amount of sunlight
DATA TABLES


Tables are an excellent way to display
data or information in an organized
fashion.
By putting data in tables one can easily
from there set up a graph to illustrate the
data.
Tables have several features in common:
First, all tables as well as graphs should have a title
to let the reader know the subject of the table or
graph. Most tables consist of a series of rows and
columns.
TITLE
ROWS
COLUMNS
GRAPHS



A graph is a chart or drawing that shows the
relationship between changing things
Common graphs use bars, lines, or parts of
a circle to display data.
Graphs must include a title and labels on the
x and y axis.
Why will we use a bar graph in our
M&M investigation?
Example of a Bar Graph
TITLE
Y-Axis
Dependent
Variable
X-Axis Independent Variable
DRY MIX

DRY MIX is an acronym to help you remember how
variables are plotted on a graph.
D = dependent variable
R = responding variable
Y = graph information on the Y-axis (vertical, up and down)
M = manipulated variable
I = independent variable
X = graph information on the X-axis (horizontal, side to side)