1. Experiment Design and Simulation
Finishing 5.2/Begin 5.3
Experiment Design and Simulation

2. 5.2 Experiment Design Recall – Correlation DOES NOT imply causation!
(Remember firemen example)
Confounding may occur due to lurking variables.

3. 3 Principles of Experimental Design
Control – comparing several treatments to a control group to avoid the effects of lurking variables.
Randomization – the use of chance when assigning subjects into control or treatments

4. 3 Principles of Experimental Design
3. Replication – Being able to conduct the experiment on as many subjects as possible.
** Larger samples  More accurate representation of population

5. 5.3 Simulation Simulation – imitation of chance behavior.
Commonly done using a random number table (back of book or on graphing calculator)

6. Simulation Example
If you flip a coin 10 times, what is the likelihood of getting a run of 3 heads or 3 tails in a row?
Assume there is a 50-50
chance of getting a heads
and tails.

7. Simulation Example Assign Digits to possible outcomes:
1 option would be:
Let {0, 1, 2, 3, 4} = Heads
and {5, 6, 7, 8, 9} = Tails

8. Line 110 from back of book:
This shows 4 simulations of 10 tosses

9. Example 2
A study finds that 40% of people prefer pepsi and 60% prefer coke.

10. Complete a simulation of 25 subjects to see how many would prefer each type of soft-drink.
Assign digits:
Pepsi: {0, 1, 2, 3} (40%)
Coke: {4, 5, 6, 7, 8, 9} (60%)

11. Use table of random digits:
pcppp ccppc pcccc pccpp cccpc
Coke = 14/ Pepsi = 11/25

12. Example 3
Suppose you shoot 68% on free-throws. How would you assign digits to begin a simulation?
1 option:
Make: {00, 01, 02, … 67}
Miss: {68, 69, 70, … 99}

13. Assignment
Page 292 #5.54 – 5.57 Only do 10 repetitions for #57b. Skip 56A