Question

What does it mean to take a sampling of a population? Why do scientists use samplings?

Answer 1

Sometimes it is not possible to enumerate each and every element of the population. Then the researcher try to select a part of the population in a way so that that part of the population represents the whole population. Now based on this part or sample the researcher does his relevant work and the result obtained based on the sample is inferred about the population after the validity checkings of the result obtained.

For example consider a company that produces matchstick want to test whether they are producing good product. Now if they does a complete enumeration here then the company has no way but to stop there business. So in these cases the company will select some matchstick from the whole lot and based on the quality of the sample, they decide whether to accept or reject the lot. Many times we may face situation where complete enumeration may be so costly that even if we want to do complete enumeration it is practically impossible. These are some reasons while we do sampling to infer about our population.