Here the initial samples are down on random basis and information from these is collected on regular basis. Itis semi permanent sample where members may be included repetitively for successive studies. Here there is a facility to select and quickly contact such well balanced samples and to have relatively high response rate even by mail.
Advantages of Panel Sampling
a.Lesser cost and time involved in the collection of information.
b.Due to fixed sample units one can measure the changes in repeated reporting.
c.Shifts of behaviour over time can be traced.
Disadvantages of Panel Sampling
a.The sample may not fully representative.
b. The members of the panel may becomes conditioned to some specific situations.
c. It may be difficult to preserve the representative character of the panel for a long time as the professional members of the panel may drop out voluntarily and may need replacement.