摘要：Known under the name of fixed sample, longitudinal sample or continuous survey, the panel is in fact a constant sample, constituted (from nominated persons) for a relatively long period of time (ten or thousand of years), on which some observations are made, measurements or repeated determinations, at constant intervals of time. That is why, the information used from its application have a greater utility, being capable to illustrate, not only the given situation (the static one, as other types of surveys) but also the evolution in time (dynamics) of the phenomenon which is the object of the market research
