# POL222H1 Lecture 7: 222-7

## Document Summary

Observational research/studies: many interesting and important political science questions cannot be examined through experiments; i. e. , we cannot control and randomly assign x, the feasible second best solution is use the actual observation of x, Y, and z in the real world: observational research/study: a research design in which the researcher does not have control over the values of the independent variable. Observational studies: basic logic of observational research, logic of observational research, individual survey data, aggregate data, variety of observational studies, cross-section studies, time-series studies, tscs or panel studies. Observations with x, y and z: suppose our observations have three variables x, y, and z, observations: x y z, 1. Relationship between y and x: we compare the average value of y across observations with different values of x, 2. relationship btw y and x, controlling for z, we compare the average value of y across different values of. X among observations with the same value of z.