The unit of analysis depicts the level at which the research is performed and which objects are researched.The essential application of sampling is that it allows for drawing conclusions about the entire population, by studying some of the elements in a population.A population element is the unit of study - the individual participant or object on which the measurement is taken. A population is the total collection of elements about which some conclusion is to be drawn.A census is a count of all the elements in a population. The listing of all population elements from which the sample will be drawn is called the sample frame.There are several compelling reasons for sampling:Lower cost: the difference between the sample costs and census costs is substantial.Greater accuracy of results: some argue that the quality of a study is often better with sampling than with a census.However, when the population is small, accessible, and highly variable, accuracy is expected to be greater with a census than a sample (Thus, a census study is: feasible when the population is small and necessary when the elements are quite different from each other).Greater speed of data collection: the time between the recognition of a need for information and the availability of that information is reduced.Availability of population elements: Some situations simply require sampling. This is the case where e.g. the population is and infinite conditions are appropriate for a census study.The advantages of sampling over census studies are less compelling when the population is small and the...