Download Midterm Study Guide

Political Science 30: Political Inquiry
Midterm Study Guide for Wednesday, April 27
Bring Your Own Blue Books! But do not bring calculators, which will neither be permitted nor
needed. You will have 50 minutes to complete the test.
Identifications. Be prepared to give a short description of some of the terms that I have defined in
lectures, say why they are important, and give an example of each concept. You will have 5 minutes
to do each identification.
The types of terms that we could ask you to identify include, but are not limited to:
• External Validity
• Hypothesis
• Intervening Variable
• Confound
• Convenience Sample
• Internet Poll
• Temporal Order
• Operational Definition
• Treatment Group
• Conceptual Definition
• Random Assignment
• Random Sampling
• Internal Validity
• Empirical Work
• The Fundamental Problem of Causal Inference
Short Answers. These will focus on Jared Diamond’s “A Natural Experiment of History” and/or
Gerber and Green’s “The Effects of Canvassing, Direct Mail, and Telephone Contact on Voter
Turnout: A Field Experiment.” For these readings, you should be able to answer questions like:
a. What type of study is this? An experiment, a quasi-experiment, a natural experiment, or
an observational study?
b. Name one hypothesis that the author/authors test. What are the independent and
dependent variables in this study?
c. For this hypothesis, has the author shown that the temporal order is correct, there is a
plausible causal mechanism, there is a correlation between the independent and
dependent variables, and that there are no obvious confounding factors?
Data Question. I may give you a short data distribution, like the distribution of Los Angeles Laker
salaries. For this distribution, you should be able to tell me what type of variable I’m using
(nominal, ordinal, interval, or ratio). You should also be able to tell me what the mode, median,
and/or mean are of the distribution. And if I ask you for the standard deviation, you should be able
to write out the formula, show your work, and compute the standard deviation.
A good way to practice is by doing the problem on the next page:
What type of variable is “cost:” nominal, ordinal, interval, or ratio? Why?
What is the median cost (as a number)?
What is the mean cost (as a number)?
What is the variance of this sample of costs (as a number)?