Variables and control

variables and control

1. Do you know the difference
between the independent
and dependent variables?

2. Independent Variable
The independent, or
manipulated variable, is a
factor that’s intentionally varied
by the experimenter.
Ex. using 25g., 50g., 100g.,
250g., 500g. of sugar in his
experiment.

3. Dependent Variable
The dependent, or responding
variable, is the factor that may
change as a result of changes
made in the independent
variable.
Ex. the size of the loaf of bread.

4. 1You drop containers of eggs
from several heights then
count the number of broken
eggs.
dependent variable
number of eggs
independent variable
heights

5. 2You exert forces at 10 pound
increments on as toy car and
measure the resulting speed.
dependent variable
speed
independent variable
force

6. 3You increase pressure at a
rate of 10lbs/in
2
and measure
the resulting volume of a
giant marshmallow.
dependent variable
volume
independent variable
pressure

7. Control Group
In a scientific experiment, the
control is the group that serves
as the standard of comparison.
The control group may be a “no
treatment" or an “experimenter
selected” group.

8. Control Group
The control group is exposed to
the same conditions as the
experimental group, except for
the variable being tested.
Allexperiments should have a
control group.

9. Example:
You are testing the affect of miracle grow (a
fertilizer) on the growth of a plant.
Control group: plant without any fertilizer at
all (just soil)
Independent Variable: type of fertilizer
Dependent Variable: amount of growth

10. When Graphing data from an
experiment, always put the
Dependent variable on the X axis
Independent variable on the Y axis