# Math W50: How do they know my opinion?
# January, 2000
Monday, January 3
Note: No Class
Tuesday, January 4
Note: No Class
Wednesday, January 5
Note: No Class
Thursday, January 6
Topic: Introduction
Topic: 7 Critical Components @ overheads/seven-critical.shtml
Topic: Measurement
Act: Survey 1 @ data/survey01.txt
Act: Survey 2 @ data/survey02.txt
Read: Utts 1-3
Vocab:
Vocab: statistics, 7 critical components,
Vocab: individual (unit), variable, value of variable,
Vocab: categorical variable, measurement variable,
Vocab: discrete, continuous, validity, reliabilty, bias, variability
#Note: Class begins 2pm in NH 295
course intro, student intros, why you are in the course
Def of stats
get student ideas (on board)
more than one use of word statistics
descriptive (summary measures)
inferential
some defs (primarily of inferential statistics)
Utts: a collection of procedures and principles for
gaining information in order to make decisions
when faced with uncertainty
Amabile: a way of taming uncertainty, of turning raw data
into arguments that can resolve profound questions
Moore: the science of gaining information from numerical data
Garfunkel: the science of drawing conclusions from data with
the aid of the mathematics of probability
dictionary: the mathematics of the collection, organization,
and interpretation of numerical data, especially the
analysis of a population's characteristics by inference
from sampling
etymology: latin: statisticus - of state affairs
political right down to etymology
key elements
data
uncertainty
information/decision-making ability
science or math?
Video - Against All Odds #1: beginning thru about 13:30, 26:00 to end
[whole thing if time -- but probably not]
Video - FAPP #6 beginning to about 4:00
Three phases of a statistical study (and outline of course)
1) collect data (statistical design)
2) organize data (data analysis)
3) draw conclusions from data (statistical inference)
Survey 1: Have students add to existing list
collect data from students, have them gather 2 more each
Quiz 0: info about students
-----------
Break
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Fill out survey 1 and survey 2
7 critical components that determine soundness of statistical studies
1) source of funding (why was it done?)
2) researcher contact
3) individuals studied and how selected
4) measurements made (quesitons asked)
5) setting
6) extraneous differences (other explanations for effect)
7) magnitude of claimed effect
example: drug to cure excessive barking in dogs (page 22)
example: US Voters Focus on Selves, Poll says (from Moore S:C&C)
example: most women unhappy in their choice of husbands (page 24)
didn't do this one
How data are organized:
units/individuals/subjects
variables
values of variables
immagine a grid layout
Some terminology
categorical vs. measurement variables
continuous vs. discrete
validity (proxies)
reliability
bias -- systematically off in same direction
variability
pictures of variability/bias possibilities (target)
Apply terminology to Survey 1
Summary -- Measuring is a difficult task
example: finding cheapest grocery store
Survey 2: Wording issues
did questions 1 and 2 in class
data: 1) 6-0; 0-6 in expected direction
2) 2-4; 2-4 in expected direction
Wording Pitfalls
Bias (Intentional or unintentional)
Elian Gonzalez
Do you agree that he should be returned to his father in
Cuba? [with US Immigration and Naturalization Service]
Do you agree that he should be allowed to remain with
his relatives in Florida? [agree with boy's attorneys]
Confidentiality and Anonymity (people may lie)
Desire to Please
"How much do you smoke?" vs. cigarette sales
didn't discuss this particular pair,
put on quiz for tomorrow
Unneccessary complexity, misunderstandings
1992 American Jewish Committee [NY Times July 8, 1994]
Does it seem possible or does it seem impossible to you
that the Nazi extermination of the Jews never happened?
(22% possible)
Does it seem possible to you that the Nazi extermination
of the Jews never happened, or do you feel certain that it
happened? (1% possible)
-------------- only got this far --------------------
"do you own stock?" cartoon
Asking the uninformed
will see an example in a video
1975 Public Affairs Act [didn't exist] (page 35)
in 1978 1/3 expressed opinion
in 1995 nearly 1/2 expressed opinion
with leading political bias, 53% expressed opinion
and tended to go with political leanings
Ordering of questions, additional information
peer pressure example (34)
Open/closed questions
museum example
Defining your terms
adolescent sex: increasing or decreasing? (page 37)
unemployment
happiness (happiness newpaper article)
"The Truth but not the Whole Truth"
Friday, January 7
Topic: Sampling
Topic: Observation and Experimentation
Act:
Read: Utts 4
Read: Utts 5
Due: HW #1 @ hw01.shtml
Vocab:
Vocab: observational study, experiment, meta-analysis, treatment,
Vocab: explanatory variable, outcome variable (response variable),
Vocab: unit, population, sample, sampling frame, sample survey, census,
Vocab: margin of error, "1 Over Root n Rule",
Vocab: simple random sampling, stratified random sampling,
Vocab: cluster sampling, systematic sampling, random digit dialing,
Vocab: multi-stage sampling, convenience sample, response rate
To conduct a study properly
1) get a representative sample
2) get a large enough sample
3) decide between observational study and experiment
Basic categories of studies
experiment
key: treatment
observational study
meta-analysis
case study (popular in media -- clip from ABC news?)
Sampling
terminology: unit, population, sample, sampling frame,
sample survey, census,
margin of error
sampling vs. census: samples are often possible, faster, accurate
Sampling Methods
SRS
stratified random sampling
cluster sampling
systematics sampling
random-digit dialing
multistage sampling
Sampling difficulties
wrong sampling frame
not reaching selected individuals
low response rate
volunteer sample
haphazard or convenience sample
Literary Digest poll (1936)
Alf Landon predicted to get 3-2 victory
volunteer response to sample from poor frame
George Gallup
Experiment terminology
over weekend: get pulse rate several times and bring numbers on monday