Transcript AP Statistics

AP Statistics
Chapter 5
Section 1
Weaknesses in data production account for
most erroneous conclusions in statistical
studies.
Do you view lying in any form as wrong?
Have you ever lied about something big, such
as choices you have made, to your parents?
How often do you lie?
Rarely
Every now and then
often
1. Have you ever specifically told your parents something that was
not true concerning school, boyfriend/girlfriend, or something you
were involved in that you know they would not like?
2. How many times did you lie to them?
0-5
6-15
16-30
31+
3. Were these lies ever discovered by your parents?
No
very few
roughly half
majority
4. Do you think dishonesty in any form is wrong?
Yes
No
Not sure
all
Have you ever lie to keep someone else
out of trouble?
Have you ever lied to get yourself out of
trouble?
Have you ever lie to keep someone else
out of trouble?
Have you ever lied to get something you
don’t deserve?
Have you ever lied having no hurtful
intentions?
Honesty
• How do you find out the truth about
honesty?
• What to ask?
• How many questions?
• How to word the questions?
• Appearance of survey?
• What can you do with a questionnaire that
would help respondents answer honestly?
Honesty
• The verbal and non-verbal act of being
completely honest and truthful in a
particular situation by not withholding any
information even if it is for the emotional or
physical protection of others.
• AP Stat class definition 09-10
Vocab
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sample
Voluntary response sample
Confounded
Statistical inference
Population
Design
Convenience sampling
Bias
SRS
Probability sample
Stratified random sample
Multistage sample
Undercoverage
Nonresponse
Response bias
Wording effects
Sampling frame
experiment
“70% OF PARENTS SAY KIDS
NOT WORTH IT.”
• The advice columnist Ann Landers once
asked her readers, “If you had it to do over
again, would you have children?”
• 70% of the nearly 10,000 parents who
wrote in said they would not have children
if they could make the choice again.
• What does this mean?
• What impression does this leave?
• How are we tricked by statistics?
Propaganda on attitude toward
foreign government
• 1940 – an experiment conducted to study the effect of
propaganda on attitude toward a foreign government
• Test of attitude toward the German government was
administered to a group of American students.
• They read German propaganda for several months.
• Tested again for their attitude toward German
government to see if their attitudes had changed.
• LURKING VARIABLE????
• Experiment results????
Design
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Method used to choose the sample from
the population.
1) SRS
2) Stratified random sample
3) Multistage sample design
SRS
A small accounting firm serves 30 business clients.
The accountants want to interview a sample of 5
clients in detail to find ways to improve client
satisfaction.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30
Table B pg. 836
Line 120 – 35 47 65 59 72 39 42 16 58 50 04 26
63 54 35 43 74 21 19 37
So, clients 4, 16, 19, 21, and 26 will be the 5 that
are interviewed.
Stratified Random Sample
Use this design when the population is large
and spread out over a wide area.
First, divide the population into groups of
similar individuals.
Then, choose a separate SRS in each
stratum and combine these SRSs to form
the full sample.
Multistage Design
Stage 1 – Take a sample from the 3000
counties in the US
Stage 2 – Select a sample of townships
within each of the counties chosen.
Stage 3 – Select a sample of blocks within
each chosen township.
Stage 4 – Take a sample of households
within each block
Cautions about sample surveys
1)
2)
3)
4)
Undercoverage
Nonresponse
Response bias
Wording effects
It is estimated that disposable diapers
account for less than 2% of the trash in
today’s landfills. In contrast, beverage
containers, third-class mail and yard
wastes are estimated to account for about
21% of the trash in landfills. Given this, in
your opinion, would it be fair to ban
disposable diapers?
Randomly Selected Groups
1. Create 5 questions regarding honesty
2. Create an appropriately designed
questionnaire