PSC Research Methods in Political Science 2 — Questions and Answers
Question 1: What is the primary purpose of a 'control variable' in statistical analysis?
- To replace the independent variable
- To isolate the relationship between the independent and dependent variables (Correct answer)
- To increase the sample size
- To eliminate qualitative data from analysis
Correct answer: To isolate the relationship between the independent and dependent variables
Control variables hold competing explanations constant, allowing researchers to isolate the specific effect of the independent variable on the dependent variable.
Question 2: A 'longitudinal study' in political science collects data on the same subjects:
- Across many different countries at one point in time
- Over an extended period of time (Correct answer)
- From a random national sample only
- Using interviews rather than surveys
Correct answer: Over an extended period of time
Longitudinal studies track the same individuals, institutions, or units over time, allowing researchers to observe change and establish temporal sequences important for causal inference.
Question 3: Which term describes the closeness between what a measure captures and what the researcher actually intends to measure?
- Reliability
- Validity (Correct answer)
- Replicability
- Significance
Correct answer: Validity
Validity refers to whether a measure actually captures the concept it is intended to measure, distinct from reliability (consistency of measurement).
Question 4: Content analysis as a research method in political science involves:
- Interviewing political elites
- Systematically analyzing the content of texts, speeches, or media (Correct answer)
- Conducting surveys of political opinions
- Observing legislative processes directly
Correct answer: Systematically analyzing the content of texts, speeches, or media
Content analysis systematically codes and categorizes written, spoken, or visual material to identify patterns, themes, or biases — commonly used to study political rhetoric and media coverage.
Question 5: In a natural experiment, researchers exploit:
- Randomly assigned treatment conditions in a laboratory
- Naturally occurring variations that approximate random assignment (Correct answer)
- Large convenience samples from social media
- Government administrative data only
Correct answer: Naturally occurring variations that approximate random assignment
Natural experiments take advantage of real-world events (policy changes, geographic boundaries, or random assignment by nature) that create treatment and control groups without researcher manipulation.
Question 6: Regression discontinuity design (RDD) is used to estimate causal effects by:
- Comparing outcomes before and after a policy change across all units
- Comparing units just above and below an arbitrary threshold or cutoff (Correct answer)
- Randomly assigning treatment to half the sample
- Matching treated and untreated units on observable characteristics
Correct answer: Comparing units just above and below an arbitrary threshold or cutoff
RDD exploits a threshold rule — such as a vote share cutoff — by comparing outcomes for units just barely above and below the cutoff, assuming they are otherwise similar.
PSC Research Methods in Political Science 2
What is the primary purpose of a 'control variable' in statistical analysis?