Introduction to Sampling


Programme: Master of Library & Information Science
Course: MLIS-09: Research Methodology
Target group: Master's students & Research Scholars


    In the previous lessons, we have seen how a researcher selects his problem, formulates hypothesis, and selects the appropriate research method for carrying out his research. In survey research, the researcher can collect data from the entire population or by studying a small portion of the population generalizations can be drawn for the population under study.

Thus the required information can be obtained in two ways namely

     1.      Census method or survey of the complete population

     2.      Sampling method

      In the census method, data is collected from each and every unit of the universe. In this method more accurate and exact information can be obtained as no unit in the population is left out. However, if the population to be studied is very large, census method is not useful because it involves lot of time, money, manpower and administrative personnel. Therefore, this method can be used only by big organizations or Government who have sufficient resources at their disposal.

Sometimes, when the population is too large, heterogeneous and geographically scattered, it is not possible to study the entire population in detail. In such cases, sampling method can be used. Sampling method makes it possible to study the selected population more intensively and exhaustively.

Some Advantages and Limitations of Sampling are listed below:

 Advantages

  • Data collection, Analysis  becomes easier
  • It saves time and money
  • Facilitates detailed study 
  •  It is convenient to manage a small sample.

     Limitations 

  •  Improper sample leads to  false, inaccurate and misleading results
  •  The size of the sample may not be representative of the total population
  •  Researcher needs specialized knowledge of sampling techniques



Activity

  We take several decisions based on sampling in our daily life For example, when we go to the market to buy grapes, we taste a few to decide whether the entire bunch of grapes is sweet and fresh. 

Identify any 3 decisions you take in your daily life based on sampling. Write your answer below:

1.  _________________________ 

2.  _________________________  

3.  _________________________