Sample is a part of a population that are used in a study for purposes of making estimation about the nature of the total population that is obtained with sampling technic. Sampling technic is more adventagous than cencus because it can reduce cost, time, and it can gather deeper information and more accurate data. It is useful to distinguish two major types of sampling technics. First, Prob bility sampling i.e. simple random sampling. Second, Non Probability sampling i.e. systematic sampling, purpossive or judgement sampling and quota sampling. All of those technics have advantages and disadvantages, therefore the selection of the sampling technic must be representatif. The sampling error can be caused by inadequate sampling technic of study.