Transcript Objective Objective: SWBAT set up an experiment with a control and experimental group Essential Questions: • What is a dependent variable? • What is an.

Objective
Objective: SWBAT set up an experiment with a control
and experimental group
Essential Questions:
• What is a dependent variable?
• What is an independent variable?
• What is an experimental group?
• What is a control group?
Tasks:
• Preview vocabulary for the day
• Take notes on new material
• Read three examples and fill in blanks
• Do independent practice and fill in blanks
• Conduct alka seltzer rocket lab
Vocabulary
1. Control Group
In an experiment, a group that
receives standard treatment
2. Experimental
Group
In an experiment, a group that
receives different treatment
3. Variable
A factor that changes and is
not constant
4. Independent
Variable
A variable that is changed by
scientists
5. Dependent
variable
A variable that responds to
changing the independent
variable
Notes 1
If you open a faucet (the independent
variable), the quantity of water flowing
(dependent variable) changes. When this
happens, you observe that the water flow
increases.
A good experiment has only one independent
variable. In the example above, only one
faucet should be opened or closed at a time
to determine its impact on water flow and
not for example turning hot and cold water
on at the same time.
Notes 2
In a controlled experiment, two virtually
identical experiments are conducted. In the
experimental group the treatment, the factor
being tested is applied. In the control group,
the factor being tested is not applied.
Effects of the treatment are isolated by
comparing outcomes in the two cases.
Notes 3
1. Start by identifying the dependent variable. In
the statement “a scientist measures the effect
of chocolate on happiness”, the dependent
variable is happiness because it depends on
chocolate.
2. Second, identify the independent variable. If a
scientist measures the effect of chocolate on
happiness, the independent variable is
chocolate. This is the variable that scientists
will change that affects the dependent variable
(happiness in this case)
Notes 4
3. Third, identify the control group. The
control group is the one that is business as
usual. In the example above about
chocolate and happiness, a group that
receives no chocolate would be the control
group because that is the standard
treatment.
4. Fourth, identify the experimental group.
This is any group that receives the
experimental treatment. In this case, it is
the group that receives the chocolate. The
happiness of this group is then compared to
the happiness of the control group.
Example One - Answer
Independent variable: hours of sleep
Dependent variable: level of aggression
Control group: group that slept as much as they
wanted
Experimental group #1: group that slept 3 hours
Experimental group #2: group that slept 6 hours
Example Two - Answer
Independent variable: alcohol
Dependent variable: sense of balance (measured
by number of stumbles)
Control group: group that drank Coke
Experimental group #1: group that drank one
ounce of alcohol
Experimental group #2: group that drank two
ounces of alcohol
Example Three - Answer
Independent variable: classical music
Dependent variable: level of relaxation (measured
by heart rate)
Control group: sitting in a quiet room
Experimental group : listened to classical music
Independent Work
Homework
1. Alka seltzer lab write-up