Population-Sample and Sampling techniques

Recently elections were held in part of some democratic country. Instead of waiting for the final election results, some media channels just went to streets and started asking people about their view on the leader of their choice. This randomly asking people about their choice of interest, reflect the choice of very small minority of overall population of the country, but carry many useful insights. Its generally referred as Exit Poll results.

The ‘Population’ in statistics doesn’t necessarily have to be human. It can be any parameter of data that possesses a common trait while ‘Sample’ is always a smaller group/subset within the population.

Sampling is done to draw conclusions about populations from samples, and it enables us to determine a population’s characteristics by directly observing only a portion (or sample) of the population. But the question arises that when we could have access to the whole population, why we care about sampling?

• Selecting a sample requires less time than selecting every item in a population
• Sample selection is a cost-efficient method
• Analysis of the sample is less cumbersome and more practical than an analysis of the entire population

There are various sampling techniques possible, which I will try to jot down:-