Chapter 13
Correlation and Regression
General Examples
Independent Variables
Nominal
Interval
Interval
Dependent
Variable
Nominal
Does a change in one variable
significantly affect another variable?
Do two scores tend to co-vary
positively (high on one sc
More for Chapter 9: Testing for the difference between two means:
#8 From your book:
From the 2008 GSS Data the mean educational attainment for liberals is 13.90 years with a standard deviation of 3.27.
The mean education attainment for conservatives is 1
Chapter 12:
Measures of Association for
Nominal and Ordinal Variables
Proportional Reduction of Error (PRE)
Degree of Association
For Nominal Variables
Lambda
For Ordinal Variables
Gamma
Using Gamma for Dichotomous Variables
Chapter 12 1
Measures o
Chapter 11: Chi-Square
Chi-Square as a Statistical Test
Statistical Independence
Hypothesis Testing with Chi-Square
The Assumptions
Stating the Research and Null Hypothesis
Expected Frequencies
Calculating Obtained Chi-Square
Sampling Distribution
Chapter 10: Cross-Tabulation
Relationships Between Variables
Independent and Dependent Variables
Constructing a Bivariate Table
Computing Percentages in a Bivariate Table
Dealing with Ambiguous Relationships Between
Variables
Reading the Research Lit
Chapter 9
Testing Hypotheses
Overview
Research and null hypotheses
One and two-tailed tests
Errors
Testing the difference between two means
t tests
Chapter 9 1
Overview
Independent Variables
Nominal
Interval
Considers the
distribution of one
variable acro
Chapter 8: Estimation
Estimation Defined
Confidence Levels
Confidence Intervals
Confidence Interval Precision
Standard Error of the Mean
Sample Size
Standard Deviation
Confidence Intervals for Proportions
Chapter 8 1
Estimation Defined:
Estimation A
Chapter 7:
Sampling and Sampling Distributions
Aims of Sampling
Basic Principles of Probability
Types of Random Samples
Sampling Distributions
Sampling Distribution of the Mean
Standard Error of the Mean
The Central Limit Theorem
Chapter 7 1
Sampling
Pop
Chapter 6:
Sampling and the Normal Distribution
Properties of the Normal Distribution
Shapes of Normal Distributions
Standard (Z) Scores
The Standard Normal Distribution
Transforming Z Scores into Proportions
Transforming Proportions into Z Scores
Finding
Chapter 4
Measures of Central Tendency
What is a measure of central tendency?
Measures of Central Tendency
Mode
Median
Mean
Shape of the Distribution
Considerations for Choosing an Appropriate
Measure of Central Tendency
Chapter 4 1
What is a measu
Chapter 3: Graphic Presentation
The Pie Chart
The Bar Graph
The Statistical Map
The Histogram
Statistics in Practice
The Frequency Polygon
Times Series Charts
Distortions in Graphs
It is important to choose the appropriate graphs
to make statistical infor
Index of qualitative variation IQV
IQV =
#1 pg 162 6th
edition
Political Views
Extremely Liberal
Liberal
Slightly Liberal
Moderate
Slightly
Conservative
Conservative
Extremely
Conservative
Total
Insert 2241.74 into
formula above
IQV=0.91 Close to
1.00 the
The Organization of Information:
Frequency Distributions
Frequency Distributions
Proportions and Percentages
Percentage Distributions
Comparisons
The Construction of Frequency Distributions
Frequency Distributions for Nominal Variables
Frequency Distrib
Calculating a regression equation
You need the following information:
The number in your sample, N
The mean of your dependent variable
and
The mean of your independent variable,
Covariance of xy
or Syx=
Variance of X or
Standard deviation of X
Variance of
REVIEW FOR EXAM #1
Be able to identify the independent and dependent variables and the correct unit of analysis in a stated hypothesis. For
example:
The average income for men is higher than the average income for women.
Or
As a state average income level
More on:
Testing Differences between
Means
Comparing Means
Weve described data.
Been able to talk about the % or
probability of certain events happening.
Weve talked about random sampling and
how the mean of an infinite number of
samples should equal t
1. Lets say youve just calculated a regression equation Y=a+bx where you are looking at
the relationship between the number of hours of TV a college student watches per week
and the students gpa.
You find that a = 4.0 and b=-.02
What is your regression eq