Sampling can be defined as the process of selection of the sample (for the study) from the target population (population of interest), with an aim to draw conclusions about the population.

Taking whole population for a research purpose is quite difficult or can say impossible because of many reasons such as time, cost, size of population etc. Hence, researchers use to select sample for their research project.

First of all, researcher selects a target population (a population who share a certain set of characteristics that the researcher is interested in studying) out of whole population. Post selection of target population, sample will be taken out of that target population which must be true representative of the target population so that the research outcome can be extrapolated in the target population.

Thus, sample is a subset of target population.

Sample is a small group of people, objects, or items which has been taken from a target population for study. Target population is the entire group of people, objects or items to which the researcher aims to generalize the study findings.

Reasons for sampling in a research

It is feasible to measure the sample instead of whole population because of different reasons. Few reasons are mentioned below:

  • Difficult to study large size of population

  • Inaccessibility of some of the population

  • Limitation of cost and time

  • Sample may provide more accurate and reliable result

Advantage of Sampling

  • Accuracy in results

  • Saves time and money

  • Feasible to conduct research

Disadvantage of Sampling

  • Chances of bias

  • Difficulty in getting true representative sample

  • Chances of error in sampling process

Sampling techniques

Selection of sample out of population of interest can be done through two techniques:

  1. Probability sampling technique

  2. Non-probability sampling probability technique