Transcript Hypothesis & Variables Powerpoint

HYPOTHESIS AND
VARIABLES
Step 3: Form a Hypothesis
 Hypothesis- a testable explanation of an
observation.
 A hypothesis is NOT just an educated guess
about what you think will happen. It must be
able to be tested!
Step 3: Form a Hypothesis
 We write the hypothesis in an If-Then statement
ex: If the amount of fertilizer is
increased,
then the height of the plant
will increase.
Variables & Controls
 A variable is anything that changes in a
scientific experiment.
 The control is what you use to compare the
results to in the end of the experiment.
There are 2 types of
variables:
 Independent
 Dependent
Step 3: Form a Hypothesis
 The Independent Variable goes after the “If”
I.V.
If the amount of fertilizer is increased,
then the height of the plant will increase.
Step 3: Form a Hypothesis
 The Dependent Variable goes after the “Then”
If the amount of fertilizer is increased,
then the height of the plant will increase.
D.V.
Now You Try:
 If you spend more time studying, then your
grade will improve.
 Independent Variable =
 Dependent Variable =
Now You Try:
 If you spend more time studying, then your
grade will improve.
 Independent Variable = amount of time spent
studying
 Dependent Variable = grade
Now You Try:
 If the temperature of the room is increased, then
the bacteria will grow faster.
 Independent Variable =
 Dependent Variable =
Now You Try:
 If the temperature of the room is increased, then
the bacteria will grow faster.
 Independent Variable = temperature of room
 Dependent Variable = bacterial growth
Variables & Controls
 A variable is anything that changes in a
scientific experiment.
 The control is what you use to compare the
results to in the end of the experiment.
2 Types of variables:
 Independent Variable: What you change.
 Dependent Variable: What changes because of
the Independent Variable.
2 Types of variables:
 Independent Variable: Cause
 Dependent Variable: Effect
Independent Variable
 Independent Variable: What you change.
 Cause
 a.k.a Manipulated Variable
 Graphed on x axis
Dependent Variable
 Dependent Variable: What changes because of
the Independent Variable.
 Effect
 a.k.a Responding Variable
 Graphed on y axis
Independent Variable vs.
Dependent Variable
Independent
Variable
Also Known
As:
Manipulated
Variable
Dependent
Variable
Responding
Variable
Results:
Cause
Effect
On a graph:
X axis
Y axis
After all of the data from the
experiment is collected, then
its time to organize the data.
Step 6: Organize your data
 Put your data into a data table
Independent
Variable
__________(unit)
Levels
Dependent Variable _______________ (unit)
Trial 1
Trail 2
Trail 3
mean range
Step 6: Organize your data
 Make the data table into a graph
 GRAPHS make it EASIER to see patterns in
the data!
Step 6: Organize your data
 How do you know what goes on each
axis of the graph?
Step 6: Organize your data
 DRY MIX
 Dependent Variable = Responding Variable = Y axis
 Manipulated Variable = Independent Variable = X axis
Parts of a graph
Y Axis
X Axis
Parts of a graph
Y Axis (Dependent
Variable)
X Axis
(Independent
Variable)
DRY MIX
Dependent Variable
Graphing:
Independent Variable
Any Questions????