LONGITUDINAL STUDIES
In the mass media area, the first major longitudinal study was done by Lazarsfeld, Berelson, and Gaudet (1944) during the 1940 presidential election. TYPES OF LONGITUDINAL STUDIES The three main types of longitudinal studies are trend study, cohort analysis, and panel study . Each is discussed in this section. Trend Studies The trend study is probably the most common type of longitudinal study in mass media research. Recall that a trend study samples different groups of people at different times from the same population. Trend studies are useful, but they have limitations. Suppose that a sample of adults is selected three months before an election and 57% report that they intend to vote for Candidate A and 43% for Candidate B. A month later, a different sample drawn from the same population shows a change: 55% report that they are going to vote for A and 45% for B. This is a simple example of a trend study 3 month before e