Importance of Sampling

A sample is taken almost always to provide statistical data on an extensive range of subjects for both research and administrative purpose. The following examples are designed to illustrate the importance of sampling in real life.

01. In opinion poll, a relatively small number of persons are interviewed and their opinions on current issues are solicited in order to discover the attitude of the community as a whole.

02. Marketing and advertising agencies conduct countless inquires to determine customers expectations, attitude, buying habits or shopping patterns. These information are useful to the manufacturers of goods for sales promotion.

03. Large lots of manufactured products are accepted or rejected by purchasing departments in business or government following inspection of a relatively small number of items drawn from these lots.

04. At border stations, customs officers enforce the laws by checking the effects of only a small number of travelers crossing the border.

05. Auditors often judge the extent to which the proper accounting procedures have been followed by examining a small number of transactions, selected from a large number of such transactions taking place within a specified period.

06. Information may be needed by concerned authority how families of different size, composition and social status spend their incomes. A small number of city dwellers may be asked to provide information on this.

07. Ministry of health and family welfare might be interested to know the status of knowledge among then adult population in a city on the danger of environment pollution by interviewing a few adults of the city.

Countries measurement of the economy, health, labor force, contraceptive use, immunization, unemployment, income, export, import, industrial products and the like rely on samples, rather than on complete enumeration, numerous surveys are being conducted to develop, test and refine hypothesis in such disciplines as sociology, psychology, demography, political science, anthropology, geography, economics, education and public health. Both local and central government make considerable use of survey data to be aware of the various population characteristics for planning and development purpose. In every case, a sample is selected because it is impossible, inconvenient, slow or uneconomical to monitor the entire population.