I-N-D-E-P-E-N-D-E-N-T variables (and
dependent and controls)
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Objectives:
 SWBAT
identify independent and dependent variables
in a controlled experiment.

Catalyst:
 Write
a hypothesis to the following question. Then
describe how you would answer it. Would a tomato
plant grow larger in natural light or artificial light?
Agenda
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Catalyst Review
How to work in Mr. Jhaveri’s lab
Make mystery goo!
What is an independent and dependent variable?
FOLDABLE
Exit Question
Catalyst Review

Hypotheses!
Is
it educated?
Is it testable?

How would you test it? What are you
changing? What are you keeping the
same?
Mystery goo! (30 minutes)

Once you have your procedure ready to go:
 Gather
 Send
 With

the materials you need.
logistics person to go get it.
your group, ANTICIPATE what will happen
Clean up: Beakers must be washed
thoroughly. Place them upside down on the
paper towels. Wipe down your desks and
floors.
Mystery Goo Hypotheses
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Let’s talk about the goo some more.
What would have happened if we added
more water? How would you test it?
What would have happened if we added
more corn starch? How would you test it?
Experimentation

Key Point #1:
A
proper experiment always has an
independent variable, dependent variable, and
control group.
 Scientists
will change one thing and measure
something else.
 If Mr. Jhaveri wears his basketball shoes, then
he will score more points in a game.
Variables

Independent Variable: The thing that I change
 Basketball

Shoes
Dependent variable: The thing that is measured
 Points

*Remember variables are always nouns!!
Good experiments…

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ONLY CHANGE 1 THING!!
You must keep everything else constant, or your
data may not be valid!
Control Group: The group without the independent
variable.
What was the control group in the basketball
experiment?
IMPORTANT!!!
Practice

Do older microwaves give off more radiation?
What is the independent variable?
IV =
Microwave Age
DV =
Radiation
Practice
Are there more love bugs in the summer or the winter
months? What is the dependent variable?
IV =
Season
DV = Amount of love bugs
Practice

Students of different ages were given the same
puzzle to assemble. The puzzle assembly time was
measured. What was the dependent variable in this
experiment?
IV =
Age
DV =
Puzzle Assembly
Time
If there are more students,
then there will be more school
buses.
IV =
Amount of students
DV = Number of school
buses
What depends on what?
IV =
DV =
Cost of Beignets
Amount of Beignets
sold
If the cost of beignets
increases, then fewer
will be sold.
If the Saints sign more free agents, then they will win
more games.
IV = Number of free
agents
DV = Games Won
Foldables!
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First flap: Real-life scenario in hypothesis form
Second Flap: Define and identify independent
variable
Third Flap: Define and identify dependent variable
Fourth Flap: Define and identify control group
Exit Question


Identify the independent variable, dependent
variable, and control group in the following
scenario.
Dr. Ayaad believes that eating artichokes can
decrease cholesterol. Dr. Ayaad recruited two sets
of patients of equal age and health and she gave
one group a normal diet and another an artichokefilled diet. She then measured the patient’s
cholesterol 2 weeks later.
COMPUTER TIME
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One computer per 2 students.

Respect these computers.
 Always
tie up cords before walking.
 Do not use excessive force when opening up the
computer.
 Be Patient!!!

Respect the time.
 If
I see you on another website without permission, you
lose your computer privileges for the day and you will
have an alternative assignment.
After you get your computer running…
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Go to this website:
http://school.discoveryeducation.com/sciencefaircen
tral/
On the brown tabs on the lower left, click virtual
lab. Then, hit get started.
Click How Does Your Garden Grow Virtual Lab
(Flash)