Catalyst (4 min) - Schurz High School
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Transcript Catalyst (4 min) - Schurz High School
Catalyst (4 min)
1.
Why is it important to communicate your
results after you perform a lab
experiment?
2.
What do we do if our results do not
support our hypothesis?
Where are we?
Last week: Observation
How
Yesterday: Scientific Method
How
we collect data in the lab
we solve problems in the lab
Today: Experiment Design
How
we design a procedure to solve
problems
Experiment Design
9/21/10
Elements of a good experiment
Beriberi
Scientists thought
bacteria caused Beriberi
Injected a group of
chickens with bacteria
Left one group of
chickens alone
Observed which
chickens got sick
Control
Independent
Variable
Dependent
Variable
Independent Variable
A change caused
by the scientist
Beriberi
Scientists thought
bacteria caused Beriberi
Injected a group of
chickens with bacteria
Left one group of
chickens alone
Observed which
chickens got sick
Dependent Variable
A variable whose
value depends
upon the
independent
variable
What we observe
in the lab
Beriberi
Scientists thought
bacteria caused Beriberi
Injected a group of
chickens with bacteria
Left one group of
chickens alone
Observed which
chickens got sick
Control
The standard that
is used for
comparison
Beriberi
Scientists thought
bacteria caused Beriberi
Injected a group of
chickens with bacteria
Left one group of
chickens alone
Observed which
chickens got sick
Constant
Something that is
held the same
throughout the
experiment
In order to make
sure we know
exactly what’s
causing a change,
we can only alter
one variable at a
time!
Examples
The number of chickens
The amount of bacteria
injected
What all of the chickens
ate