View
227
Download
6
Category
Preview:
Citation preview
PS 235 Lecture NotesSpring 2010Clayton ThyneBased on Frankfort-Nachmias & Nachmias, Chapter 3
We recall from Ch.1 that social science is validated by (1) reason and (2) experience…or (1) the conceptual/theoretical and (2) the observational/empirical
Chapter 2 focused on #1: reason/theory
This chapter focuses on how you can go about testing your theory
We recall that scientific research must be empirically verifiable
This requires that we are specific about our hypothesized relationships
Scientific? How can we best promote democracy? How does state wealth impact the likelihood
of coups? Would McCain have reduced troops in Iraq? Should I support the health care bill?
Group A Group B
Mean = 51 Mean = 49.9
20
% g
ot
95
80
% g
ot
40
51
% g
ot
45
49
% g
ot
55
Mode = 51Mode = 40
Def – the most elementary part of what is to be studied
1st step in testing your theory Helps avoid..
Ecological fallacy – generalizing from groups to individuals
Individualist fallacy –generalizing from individuals to groups
We love
democracy
!
Nop
e.
Your theory should culminate in a hypothesis, which is a tentative answer to your research question.
A hypothesis should… Be clear Be specific Be testable Be value-free
How we operationalize concepts Can be clearly identified and measured
ConceptsState wealthDemocracyEducationRegime stability
VariablesGDP/capitaPolity scores% literateYears since coup
Dependent (DV) = the concept to be explained Independent/explanatory (IV) =
induces/explains DV Y = f(X)
Plant growth = water + sun + soil Civil war onset = Education + GDP/capita + pop
Control variables (‘other’ IVs) Avoid omitted variable bias
Endogeneity issues …or does…education = civil war + GDP/capita +
pop?
Continuous = no minimum-sized unit (e.g., GDP/capita) Discrete = have a minimum size unit (e.g., rich/poor) H: Higher levels of democracy will lead to more state
wealth. Wealth (DV) = democracy (IV)
Continuous = income/capita
Discrete = Richer/poorer than median GDP/capita
Continuous = polity score
Discrete = democracy/non-democracy
H: Higher levels of democracy will lead to more state wealth.
Wealth (DV) = democracy (IV)
Continuous = income/capitaDiscrete = Richer/poorer than median GDP/capita
Continuous = polity score Discrete = democracy/non-democracy
2.5
33.
54
4.5
gdpp
c
-10 -5 0 5 10polity2
| dem rich | 0 1 | Total-----------+----------------------+---------- 0 | 3,775 1,201 | 4,976 1 | 443 962 | 1,405 -----------+----------------------+---------- Total | 4,218 2,163 | 6,381 0
12
34
p 50
of g
dpp
c
0 1
-50
510
p 50
of p
olit
y2
0 1
http://www.uky.edu/~clthyn2/PS235_GenEd/home.htm
…or ask Jason or me.
Recommended