Bivariate Regression
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12
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17
10
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Example (to review correlation and to introduce regression)
o Suppose that a researcher collected the following data on years of education and number of
children for a sample of 10 married adults.
Note t
Pearson Correlation
Blind dating example to illustrate independent and dependent variables
o Have class determine how they would find out about a blind date without asking anyone
anything directly about the person
o Independent: the variable that is the c
Review Day #5
Review example of confidence interval and hypothesis test for a mean
o A local police department wants to estimate the average speed of vehicles along a main street
where the speed limit was 35 mph. However, the police department does not bo
Differences between means and differences between proportions
Calculating a mean or proportion from a sample and using this information to make a prediction
about the corresponding mean or proportion in the population is often not enough we often need to
Confidence intervals and hypothesis tests for proportions
o Recall from earlier in the class what a proportion is and where it comes from (a frequency
distribution)
Gender
Male
Female
Total
Frequency
961
1083
n=2044
Proportion
(called if from a sample)
.4
Review Day #4
Suppose we are interested in knowing about the typical age of an adult in the U.S. we will use
census and sample data to examine this from multiple angles
Since age is a question that is asked on the census, we actually know what the populat
One sample t-test for means
In the last lecture we were exploring data from a sample who had been asked about the number of
traumatic events a person experienced over the past 5 years. Briefly, the results for the variable were:
o ,
o 95% confidence inter
Hypothesis Testing
Brief description of my medical sociology research on psychosocial stress and mortality
Ask class to write down their best guess of the average number of traumatic events that happen to a
person, their spouse, their siblings, their pare
The t Distribution
The story of Gosset and Guinness
o Gossets job was to determine the alcohol content of the finished beer from just 5 barrels for each
batch (you dont want to open all the barrels as this releases the carbonation and may let bacteria
in
Confidence Intervals
The concept of a Margin of Error (MOE)
o 99.00% confidence in drawing a sample that is within 2.575 s.d. of really means
we are 99% sure that we will draw a sample such that
i.e., we are 99% sure that is between
o 95.00% confidence
Working with the Sampling Distribution: Confidence Levels, , and the Multiplier
Suppose we have a population of 500 people, where and
o Trial: Draw a sample of 150 people (note: this is a repeated trial, without replacement, where
order is not important)
Review Day #3
Frequency distribution for household size, based on data from 2044 people (which we will treat as a
population)
Household
size
1
2
3
4
5
6
7
8
9
10
11
12
Totals
Frequency
612
718
318
224
85
46
24
6
6
3
0
2
n=2044
We can determine a number o
Sampling Distributions, the Law of Large Numbers, and the Central Limit Theorem
Consider the following population of 4 individuals, from which we will draw two people at random:
o
Population consists of persons A, B, C, and D
o
Suppose we asked every per
Probability and Cumulative Probability
The following data comes from a study of a small population of 2843 households, with each households
representative being asked how many vehicles the household has.
If we want to do a simple trial, selecting one hou
Introduction to Probability
Blackjack
o Break students into groups to play blackjack; ask if anyone knows how a casino dealer will play
(dealer must stand on 17, i.e., must draw if total is 16 or less)
o Play a couple of hands to show that the dealers str
Measures of Variability II
If someone were to ask you about your commute, what types of things could you tell them? (origin,
destination, direction, type of transportation, what you encounter along the way, etc.); ask what the most
important aspect is; ar
Review Day #1
Hand out data sheet
Put up GSS questions on board and remind students of the definitions of unit of observation and
variable
o What is your gender? (1=Male; 2=Female)
o What race do you consider yourself? (1=White; 2=Black; 3=Other)
o Respon
Measures of Central Tendency
Measures of central tendency: summarizing in one number what the most typical response was for a
particular variable. There are three types of measures: the mode, the median, and the mean
o Mode
Definition: the most frequentl
Review Day #1
Hand out data sheet
Put up GSS questions on board and remind students of the definitions of unit of observation and
variable
o What is your gender? (1=Male; 2=Female)
o What race do you consider yourself? (1=White; 2=Black; 3=Other)
o Respon
Organizing your Data
Gather example data about reality TV
o Ask how many in the class watch at least one reality TV show, list shows on boards
o Ask them the reasons why they watch (hopefully one reason will be because the characters are
interesting)
o As