What is the advantages of random sampling?

Answer 1

Please read related link on what defines a simple random sample. When a sample is done randomly, then every item in the population has an equal chance of being selected. An advantage of random sampling is unbiased statistics. An unbiased statistic has the characteristic that as the sample size increases, the statistics from the sample approaches the true values of the population. This is true if the probability distribution of the population is not changing with time, or as a result of being sampled. Using a random sampling method does not guarantee statistics free of bias. For instance, if I wanted to produce a biased result, I might ask loaded questions. I might also pick particular city, say Chicago, and ask people at random for their favorite team. Obviously, my statistic is not valid outside of Chicago. A second advantage is that the statistical analysis related to sample distributions, hypothesis testing, and sample size determinations assume that the sample is a simple random sample. Remember. the goal of all sampling methods is to obtain information that is representative of the population that is under study. It may not be practical to do a random sample in many cases. For example, suppose I want to know how many people die before age 45 in the world. My random sample would have to include people any country. You can find more information on random sampling and other methods by searching under random sampling methods.