HW 7 1. Does Gingko protect against Alzheimer's? 40 elderly adults were recruited from a local senior center. Half took Ginko for three months (coded as a 1); the other half took placebo (coded as a 5). At the end of the experiment, all participants took a Word-Production task, a standard neurological task that measures cognitive skills and has national norms. What is (are) the independent variable(s)? 2. What is (are) the dependent variable(s)? 3. Phase 1: Use the estimation approach to analyze these data. Phase 2: Analyze these data using the NHST approach. Phase 5: Based on the results, what should be your biggest concern for internal validity?