AMDM
Spring 2013
Unit 2
Date
Tues 1/29
Topic
Assign Semester Project/
Designing Samples
Assignment
III: SAS 4, p.18 (1-6, 10)
Wed
Simple Random Samples
p. 2- 3
III: SAS 4, p. 21, 11
Thurs 1/31
More Designing Samples
p. 4
III: SAS 10 p. 51
Fri
Vocab Quiz
Project Part A
Mon 2/4
More Designing Samples
p. 5 and 6
Project Part A
Tues 2/5
Project Part A Due + Review
Web
Review
1/30
2/1
2/6
Finish Classwork
Thurs 2/7
QUIZ
Fri
Designing Experiments
p. 7 - 8
III: SAS 1, p. 6, (13-19)
Mon 2/11
Designing Survey Questions
p. 9
III: SAS 8, p. 45 (1 – 2)
Tues 2/12
IRB - III: SAS 2, p. 11 (1-5) + Review
p. 10
Project Day- Part B
WEB 2/13
QUIZ + Project Part B Due
Thurs 2/14
Vocab Quiz #2 + p. 11 - 13
Fri
Holiday
2/8
2/15
Mon 2/18
No School!
Tues 2/19
3rd In Class Project Day Part C
Wed
2/20
UNIT 6 TEST!
Thurs 2/21
Presentations
Fri
Presentations
2/22
1
Designing Samples Notes
Two different types of studies:
1. observational study –
2. experiment –
Variables:
explanatory:
response:
lurking:
confounded:
Group Being Studied:
population:
sample:
Types of samples:
voluntary response sample:
ex:
convenience sampling:
ex:
Systematic sampling:
ex:
Bias
2
Simple Random Samples
Steps:
1: Assign a numerical label to every individual in the population.
2: Use the table of random digits to select labels at random.
1.
a) Beginning at line 102, what are the first 2 digits?
b) Which two students would be chosen for the activity according to the labels the
teacher assigned?
c) Suppose the teacher wanted to select four students from the group of students
in the table. Which students would be selected if she selected digits starting on
line 104?
3
2. Consider a group of 100 students.
a) How would you assign labels to this group?
b) Describe how you would use the table of random digits to select 5 students
from this group of 100.
c) Beginning at line 110, which 5 labels would you select?
Definitions
Simple Random Sample (SRS):
Stratified random sampling:
Systematic Sampling
Cluster Sampling:
Block Sampling:
Convenience Sampling:
Table of Random Digits:
4
More Designing Samples
Cautions about Surveys:
Undercoverage:
Nonresponse:
response bias:
wording of questions.
Quiz Review
Vocabulary: Write the definitions for the following vocabulary terms. **These are not ALL
of the vocabulary terms you need to know for the quiz. Review all the vocabulary you can
find within this packet and the SAS activities.
1
Bias
2
voluntary response sample
3
Population
4
Sample
5
stratified random sample
6
Undercoverage
7
observational study
5
8
Experiment
9
lurking variable
10
confounded variables
11
experimental units
12
Nonresponse
13
Blind/ Double Blind studies
Short Answer: answer in complete sentences.
13. What is the difference between an observational study and an experiment?
14. Why do we study samples instead of an entire population?
15. Starting line 134, randomly select 10 people from the list:
Tom
Katie
Nick
Patricia
Whitney
Morgan
Dorothy
Darren
Bonnie
Danny
Danielle
Hillary
Brittany
Michael
Drew
Eddie
Alex
Madi
Ryan
Jennifer
Brian
Caroline
Jarrett
Ryan
Ansley
Darby
Melonie
Stacy
Dean
Daniel
Mark
Dana
Tammy
Nicole
Adrienne
Calen
Matt
Eric
Megan
Caitlin
Stephen
Nathan
6
Designing Experiments
Two Types of Units Being Studied:
1. Experimental Units:
2. Subjects:
Treatment:
Factors:
Randomized Comparative Experiments
Randomization:
Completely Randomized Designs:
Statistically Significant:
Comparative Experiments
Placebo Effect:
Control Group:
How to reduce problems with experimentation:
1. B lind & double blind:
2. Make experiments believable and duplicate conditions you want to study in
order to avoid a lack of realism.
7
Vocabulary:
Review
Observational Study
Experiment
Confounding
Population
Sample
Voluntary Response Sample
Bias
Simple Random Sample (SRS)
Random Digits
8
Probability Sample
Stratified Random Sample
Undercoverage
Nonresponse
Experimental Units
Subjects
Treatment
Completely Randomized Design
Statistically Significant
Block Design
9
Short Answer:
1. A group of cat lovers is conducting an experiment on 24 Persian cats. They want to
know whether or not feeding them moist food will affect their weight compared to the
dry food they eat currently. Each group will consist of 12 cats and Group A will continue
feeding the cats dry food while Group B is going to start feeding them moist food.
a) are the cats experimental units or subjects?
b) Which group is the Control group?
2. A company that is trying to come out with a new drug to help depression is going to do
an experiment testing their new drug. The experiment is being conducted with 27
patients. 9 patients in Group A are receiving sugar pills, 9 patients in Group B are actually
receiving the drug in pill form.
a) Are the patients involved experimental units or subjects?
b) Which group is the Control group?
c) What outcome would show the placebo effect?
3. This same company (from number 2) is going to try another experiment with the drug.
For this experiment, the administer of the pills is not going to know who gets the sugar
pill and who gets the actual pill testing the new drug. The administer tracks the
condition of the depression in the patients and reports this to the company. The
company finds that Group A is in better condition than Group B.
a) Is this experiment a double blind? why or why not?
b) Which group receives the placebo treatment?
10
TEST REVIEW
Short Answer
1. What is the difference between the population and the sample? Write your own
example and list the population in your example as well as the sample.
2. Write your own example of an observational study.
3. Write your own example of an experiment.
4. What is the difference between experimental units and subjects? Give an example of
each.
5. Write an example of your own experiment, where there are 2 groups. Then state
whether the groups consist of experimental units or subjects. Also list which group is
the control group.
6. Mrs. Bradley is randomly selecting four of her friends to go to the Georgia vs. Georgia
Tech game with her in a few weeks. Listed below are the names of the friends she is
choosing from. Using line 130 from the random digits table, select a simple random
sample. Circle the names of the friends selected.
Tom
Bryan
Ashley
Thomas
Kristine
Ryan
Nick
Katie
James
11
7. Listed below are the top 25 teams in the BCS rankings of college football. Using line
136 from the random digits table, select a simple random sample of 7 teams, then circle
the names of the teams selected.
Oregon
Auburn
TCU
Boise State
Utah
Alabama
Nebraska
Oklahoma
Wisconsin
LSU
Ohio State
Missouri
Stanford
Michigan State
Arizona
Iowa
Oklahoma State
Arkansas
South Carolina
Mississippi State
Baylor
Virginia Tech
Nevada
Florida State
North Carolina
State
12
Vocabulary: Words (you should know) and their definitions. You will not have a word
bank on this test.
1. Observational study:
11. Nonresponse:
2. Experiment:
12. Bias:
3. Population:
13. Double Blind:
4. Voluntary response sample:
14. Randomization:
15. Experimental Units:
5. Convenience sampling:
6. Simple Random Sample (SRS):
16. Subjects:
7. Table of Random Digits:
17. Confounding:
8. Probability Sample:
18. Block Design:
9. Stratified Random Sample:
19. Statistical Significance:
10. Undercoverage:
20. Treatment:
… and the others from SAS activities!
13