In a 2011 study, researchers explored whether there is an association between presidential TV advertising and voters’ opinions of the candidates. The researchers analyzed data about the Bush-Gore 2000 presidential election, including local ratings of TV shows in which presidential advertisements were run and interviews conducted in 2000 by National Annenberg Election Survey. The study concluded that a voter who had been exposed to more advertisements for a certain candidate tended to have a more positive opinion about that candidate.
a. Is the study an experiment or an observational study? Explain.
b. What are the explanatory and response variables?
c. In states where the presidential race was close, the candidates had a lot of “on-the-ground” interaction with voters, hoping to improve voters’ opinions of them. Even if the race was not close in neighboring states, the states often still received the local TV presidential advertising from the state with the close race. Why did the researchers analyze only voters in such neighboring states where the race was not close?
d. What is the conclusion of the study? Does this mean there is causality or only an association between the two variables? Explain.