1. CONTROLLED COMPARISONS

2. READING Pollock, SPSS Companion, chs. 4-5

3. Testing Hypotheses Experimental Designs: The True Experiment: pre-measurement, treatment, post-measurement for “test” and “control” groups The Natural Experiment: external or ascriptive factors (“nature”) define test or control groups Controlled Comparisons: “How else?” and holding rival causes constant Example: Opinions on Gun Control

4. Support for Handgun Control: Comparing Percentages

5. Support for Handgun Control: % Within Groups A.Gender not Partisanship ______% in Favor_______ Gender Dems Repubs Female 60 60 Male 45 45 B.Partisanship not Gender _______% in Favor_______ Gender Dems Repubs Female 60 45 Male 60 45

6. C. Partisanship and Gender ________% in Favor________ Gender Dems Repubs Female 65 55 Male 40 30

7. RETHINKING GUN CONTROL __Democrats____Republicans__ Female MaleFemale Male For 70 50 50 30 Agst 30 50 50 70

8. The Analytical Challenge(s) 1.Establishing cause-and-effect 2.Considering unobserved (lurking) variables— the “What else?” question 1.Assessing roles of other X variables 2.Inventing alternative explanations for any observed relationship (how might we interpret a positive relationship between poverty and radicalism?)

9. Looking Ahead and Beyond…. 1.What if all bivariate relationships support the the separate hypotheses? What then? 2.Check relationships among the independent variables: Are they measuring different things? Or the same? 3.Can we identify the relationship between Y and, say, X 1, while controlling for the effects of X 2 and X 3 ?