Transcript ch3_frank
PS 235 Lecture Notes Spring 2010 Clayton Thyne Based 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? 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 Mean = 51 Mode = 40 49% got 55 Group B 51% got 45 20% got 95 Group A 80% got 40 groups Mean = 49.9 Mode = 51 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 Concepts State wealth Democracy Education Regime stability Variables GDP/capita Polity scores % literate Years 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 Continuous = polity score Discrete = Richer/poorer than median GDP/capita Discrete = democracy/nondemocracy H: Higher levels of democracy will lead to more state wealth. Wealth (DV) = democracy (IV) Continuous = polity score Discrete = democracy/non-democracy 0 0 2.5 -5 1 3 0 2 | dem rich | 0 1 | Total -----------+----------------------+---------0 | 3,775 1,201 | 4,976 1 | 443 962 | 1,405 -----------+----------------------+---------Total | 4,218 2,163 | 6,381 3.5 gdppc p 50 of gdppc p 50 of polity2 5 3 4 10 4 4.5 Continuous = income/capita Discrete = Richer/poorer than median GDP/capita -10 -5 1 0 polity2 5 10 http://www.uky.edu/~clthyn2/PS235_GenEd/ home.htm …or ask Jason or me.