POLSCI 240 Lecture Notes - Lecture 2: Internal Validity, Causal Inference, Motivation
10 May 2018
School
Department
Course
Professor
Political Psychology
9.05.16 Lecture Notes
The Basics of Political Participation
Primary research methods that political psychologists use
o Case studies, in-depth interviews (small n)
▪ Learn the idiosyncrasies of a given unit
▪ Overcomes the limitations of public opinion surveys, such as lack of depth
▪ Limited ability to generalize (lower generalizability)
o Public opinion surveys (usually large n)
▪ Easy to administer
▪ Reliability is questionable, are people really giving meaningful answers
o Experiments
▪ Interested in causal relationships
▪ Causality is hard to measure in a public opinion survey
▪ Direction of causality is also hard to assess, which is why experiments are useful
o Ex: the problem of causal inference
▪ Does negative ads depress voter turnout?
▪ There are alternative explanations
▪ Maybe people who exhibit political distrust are more likely to remember negative
ads and the political distrust is what is causing the lack of turnout
o Random assignment in experiments
▪ Instead of observing the independent variable, the experimenter manipulates the
independent variable
▪ Randomly people to view negative or positive ads and observe the turnout
o Innovations in experimentation
▪ Experiments have their own limitations
▪ Strict control implies artificial environments (decreases generalizability because the
generalization is a jump from an artificial context to the real world) and
unrepresentative samples (experimentation is costly so most of the samples are
college students)
▪ External and internal validity
▪ New methods to helping overcome some of these limitations
• Survey experiments
o Combining survey and experiment = embedding experimentation into
the survey makes sample more representative
• Field experiments
o Experiment occurs within people’s day-to-day lives
o Ex: Experiment on turnout with letters (neighbors will know if you
voted)
• Natural experiments
o Find a situation in the world – some variable is already naturally
assigned to people – and you study the consequences of that
When (and why) do or don’t people participate?
o They can’t lack of resources
o They don’t want to lack of intrinsic motivation
▪ Civic duty, morality
o Nobody asked lack of extrinsic motivation
▪ Social pressure, reputation
Traditional rational choice approach
find more resources at oneclass.com
find more resources at oneclass.com
