PSYCH 3010 Practice Exam Questions and Correct Answers

Multivariate designs involve more than two measured variables. Three criteria for establishing causation Covariance, temporal precedence, and internal validity Longitudinal design can provide evidence for temporal precedence by measuring the same variables in the same people at several points in time. When would a longitudinal study be used? To study changes in a trait or an ability as a person grows Cross-sectional correlations Test to see whether two variables, measures at the same point in time, are correlated Example of cross-sectional correlations A study reports that the correlation between mothers' overvaluation at Time 4 and children's narcissism at Time 4 was r = .099. Because both variables in a cross-sectional correlation were measured at the same time, this result alone cannot establish temporal precedence Autocorrelations Evaluate the correlation of each variable with itself across time (test-retest reliability)--measured on two different occasions Cross-lag correlations Show whether the earlier measure of one variable is associated with the later measure of the other variable. They address the directionality problem and help establish temporal precedence Covariance When two variables are correlated and their 95% CIs do not contain zero, there is covariance Temporal precedence By comparing the relative strength of the two cross-lag correlations, the researchers can see which path is stronger. If only one of them is statistically significant, the researchers move a little closer to determining which variable comes first and closer to establishing causation Internal validity When conducted simply- by measuring only the two key variables-- longitudinal studies may not help rule out third variables Multiple regression statistical technique used to help rule out some third variables, thereby addressing some internal validity concern