Panel

A panel refers to a survey sample in which the same units or respondents are surveyed or interviewed on two or more occasions {waves). Panels can give information about trends or changes in the characteristics of a given population over a period of time. A panel usually can measure changes in the characteristics of interest with greater precision than a series of independent samples of comparable size. A survey using a panel design is often called a "longitudinal survey," which is one particular type of repeated survey.

The sample design for a panel is very different from the one for an independent sample or a series of independent samples. In the sample design for a panel, more stable stratification variables over time can (and should) be ...