A panel interview may be composed of either individuals or corporate units. It is a convenient method of obtaining information about the continuing behaviour of a group or panel of respondents. The very nature of the panel interview is that the group comprising the panel member is interviewed on the same or similar topics at regular intervals over a reasonable period of time. Since the data are obtained for a fixed panel or group over a successive period the basis is provided for determining trends and changes over a length of time. The panel interviews are not greatly different form setting up any other type of sampling operations.