Abstract:

Finding samples representing segments of the general population when the rate of strike (percentage of the segment in total population) is inferior to 20%, is becoming a common performance asked from the practitioner by client marketing companies. This is at least the experience of SECED - Research International in France. The survey of practice within this agency indicates clearly that not only targeted samples of the population, but very narrow target samples form an increasing part of the commissioned work of this agency. Special techniques, not resorting to the well established statistical sampling techniques, are currently used to cope with this problem. They are presented in decreasing order of statistical orthodoxy, from the "telephone screening" to the "introduction technique", through use of data-files and statistical inference, with remarks on their cost efficiency. None of these techniques is actually original, and the paper is mainly intended to initiate discussion and sharing of experience on the practical ways and means of finding these "oiseaux rares".