Target 5: Identify the control and experimental
groups in an experiment.
The Control Group
Gets no experimental treatment or
independent variable
Controls are NOT being tested
Controls are used for COMPARISON
All experiments must have a control
group.
Experimental group
Receives some condition of the
independent variable.
Example: Control vs. Experimental Groups
 Mr. Smithers thinks that a special juice will increase
the productivity of workers. He creates two groups of
50 workers each and assigns each group the same task
(in this case, they're supposed to staple a set of papers).
 Group A is given the special juice to drink while they
work. Group B is not given the special juice. After an
hour, Mr. Smithers counts how many stacks of papers
each group has made. Group A made 1,587 stacks,
Group B made 2,113 stacks.
Identify:
Control Group –
Experimental Group –
Independent Variable –
Dependent Variable --
Answer:
 Control Group
 Experimental Group
 Independent Variable
 Dependent Variable
Group B
Group A
Special Juice
Number of Stacks
Target 6: Create a graph that shows the trends in
the data with all the appropriate labels.
Examples of Good and Bad Graphs
Graph 1
Graph 2
Which graph is the “good” graph? Why?
What is wrong with this graph?
 There's no title. What's it a graph of? Who knows?
 There are no labels on the x or y axis. What are those
numbers? What are the variables? Who knows?
 There are no units on the x or y axis. Is this a graph of
speed in miles per hour or a graph of temperature?
 Somebody played "connect the dots". This should be
a nice straight line which goes through the points or a
curve that tends to follow them. Shows the TRENDS!
Target 7: Write a Conclusion
 Statement should accept or reject the hypothesis.
 Should make recommendations for further study
and possible improvements to the procedure.
Conclusion Example:
 Mr. Smithers needs further testing of his
hypothesis. The special juice does not increase the
productivity of the workers in this experiment.
However, this could be due to an inconsistency in
the experiment. Another experiment will be run.
Group A will be given special juice one hour before
the activity and group B will be given the same
amount of water one hour before the activity.
With this change in procedure the hypothesis will
be tested again and data will be recorded.