Transcript Political Research and Statistics

Hypotheses
9/3/2013
Readings
• Chapter 1 The Measurement of Concepts (1423) (Pollock)
• Chapter 2 Measuring and Describing Variables
(Pollock) (pp.28-31)
Homework:Backing Up Your Data
• Save the Information from the CD onto
another media
– Flash Drive
– Edshare
• These are just data files, not a
program
We Will Use the Full Version
Make Sure you move these files
The Files that We Will use
• Data Files on the Pollack CD
• GSS2008.SAV- the 2008 General Social Survey Dataset
– n=2023
– 301 variables
• NES2008.SAV- the National Election Study from 2008.
n=2323
– 302 variables
• STATES.SAV- aggregate level data for the 50 States. N=50
– 82 Variables
• WORLD.SAV- aggregate level data for the nations of the
world. n=191
– 69 Variables
OPPORTUNITIES TO DISCUSS
COURSE CONTENT
Office Hours For the Week
• When
– Wednesday 12-3:30
– Thursday 8-10, 11-12
– And by appointment
Course Learning Objectives
1. Students will learn the research methods
commonly used in behavioral sciences and
will be able to interpret and explain empirical
data.
2. Students will learn the basics of research
design and be able to critically analyze the
advantages and disadvantages of different
types of design.
How we measure our Variables
UNITS OF ANALYSIS
Units of analysis
• Aggregate
• Individual
• Make sure you measure your independent
and dependent variables the same way
HYPOTHESES
What Is a Hypothesis
• An educated Guess
• These are explicit Statements
• They Try to explain a relationship
• But they are only tentative until tested
Stating a hypothesis
There is a _____(direction)________relationship
between ________and ____________
The Null Hypothesis
• The Statement of No
Relationship
• What we want to
disprove
• The Basic start of
research
H0
On Stating the Null “there is no
relationship between the
independent and dependent
variable”
Correlative Hypothesis
• “there is a relationship
between x and y”
• A very weak statement
Positive Hypothesis
• A directional hypothesis
• “as the independent
variable increases, the
dependent variable
increases”
Positive Relationship
On Stating a Positive relationship:
There is a positive relationship
between my independent variable
(church attendance ) and
dependent variable (support for
McCain)
Negative Relationship/Hypothesis
• “As the independent
variable increases, the
dependent variable
decreases”
• Also called an inverse
hypothesis
Minimum Wage
On Stating a negative hypothesis:
There is a negative (inverse)
relationship between “age”
(independent) and “minimum
wage” (dependent variable)
Logarithmic
• Y=log(x)
• The dependent variable
changes rapidly,
followed by less change
An Example
Another Log relationship
Curvilinear
• The Relationship forms
a curve!
• The dependent variable
increases to a point,
and which point it
begins to decrease
The Laffer Curve
• The Debate over taxes
• Ben Stein
Fuel Efficiency
Crime
More
CHARACTERISTICS OF GOOD
HYPOTHESES
Good Hypotheses are Empirical
• Something that we can Measure
Good Hypothesis are
Generalizable
• Apply to more than one
case
Specific
• Always State a direction
• Always identify the iv and
the d.v.
• Avoid the correlative
hypothesis
Good Hypotheses are Plausible
• There needs to be a
Real world justification
for why they are related
• If Chewbacca lives on
Endor, you must acquit
Good Hypotheses are Testable
• You have to be able to test your hypothesis or
it is just speculation.
Non-Tautological
• Your independent and
dependent variables are
separate concepts
A Test of Scientific Knowledge
A CAUSAL HYPOTHESIS
What is a causal hypothesis?
• The Boldest Hypothesis
out there
• A relationship that will
occur 100% at all times,
no exceptions
• Difficult to Prove
To Prove a Causal Hypothesis
1. A Change in the Independent Variable will
always cause a change in the dependent
variable.
2. A change in X always precedes a change in Y
3. X is necessary and sufficient to cause a
change in Y
Causality is the heart of scientific
knowledge!
Close, But not a law
• Maurice Duverger
(1957) wrote that
"the simple-majority
single-ballot system
favors the two-party
system" and that
"multimember
districts favor
multiple parties".
Hypothesis- PR
systems will have
more parties
MEASUREMENT
What is Measurement
• How we quantify our concepts
• The most basic measures talks about how
much (votes, money, etc).
Good Measures
• Start with Good
Operationalization
• Are reliable and
accurate (valid)
• Can actually be done
• This is difficult
Bad Measures
• Are unreliable
• Are inaccurate (valid)
• This leads to bad
conclusions
RELIABILITY AND VALIDITY
Measurement Validity
• A measure is valid
if it measures
what it is
supposed to
measure
• The measure and
the concept
correspond
Operational Validity
• The measure does what it says
• This can be difficult to establish
Face Validity
• The simplest way to
seek validity
• The Measure looks
good on its face
• We ask People, use the
literature
• Problems?
Content Validity
• Using several measures
of a concept to get at
the whole concept
• Good for multidimensional concepts
(e.g. political
participation)
St. Edward’s Admissions
• $50 Application fee
• High School Transcript
• SAT or ACT
• Essay
• Recommendation Form
Trust in Government
•
•
•
•
Trust the Federal Government
Is the Government Run for the Benefit of All
Do People in Government Waste Tax Money
Are Government Officials Crooked
Freedom House Index
• 27 Questions
A. Electoral process
B. Political pluralism &
participation
C. Functioning of
government
D. Freedom of expression &
belief
E. Associational &
organizational rights
F. Rule of law
G. Personal autonomy and
individual rights
The Misery Index
Predictive Validity
• Using a measure to
predict a future
outcome
• This is very difficult in
the social sciences
The NFL Combines
• 40-yard dash
• Bench press
• Vertical jump
• Broad jump
• 3 cone drill
• Shuttle run
Newsweek from 1978
The LSAT’s
• The LSAT is designed to
measure skills that are
considered essential for
success in law school
• The LSAT is a strong
predictor of first-year
law school grades
• What doesn’t it
measure?