INTRODUTION<br /> The need for adequate and reliable data is ever increasing for taking wise decisions in different fields of human activity and business is no exception to it.<br /><ul><li> Complete enumeration survey or census method
Sampling method </li></li></ul><li>CENSUS METHOD<br /> Data are collected for each and every unit belonging to the population or universe which is the complete set of items which are of interest in any particular situation .<br />Advantages of census method are:-<br /><ul><li>Information can be obtained for each and every unit.
Greater Accuracy.</li></li></ul><li>SAMPLING METHOD<br /> In the sampling method instead of every unit of the population only a part of the population is studied and the conclusions are drawn on that basis for the entire population.<br />Purpose of sampling :-sampling is only a tool which help to know the characteristics of the universe or population by examining only a small part of it. The value obtain from the study of sample ,such as the average and variance ,are known as ‘statistic’. Such value for the population are called ‘parameters’.<br />
PRINCIPLES OF SAMPLING <br />Principle of ‘Statistical Regularity’ ,and<br />Principle of ‘Inertia of Large Numbers’.<br />
METHOD OF SAMPLING<br /> when a sample is required to be reflected from a population ,it is necessary to decide which method should be applied .<br /> The various method of sampling or sampling design can be grouped under the head as random sampling and non-sampling .<br />Random sampling referred to as probability sampling since if the sampling process is random ,the law of probability can be applied ;thus the pattern of sampling distribution needed to interpret and evaluate a sample is provided.<br />Non –random sampling is selected on basis other than probability considerations such as expert judgment ,convenience or some critria . The most important aspect of non –sampling worth nothing is that its subject to sampling variability but there is no way of knowing the pattern of variability in the process.<br />