Secondary data and Methods for collection of secondary data in statistic?

           Secondary data:

The data that have already been collected by someone and the statistic techniques are applied at least once on such data, are called secondary data.

 When statistical methods are applied on primary data, then they lose their original shape and become secondary e.g. if the data in different census years are again used to measure the changes in the population growth, sex ratio, mortality rate etc.

Methods for collection of secondary data:

Secondary data are those, which have already been collected by someone for their own use and now he same data is used by different persons for another purpose. Such data can be collected from the following sources.

1.                 Official sources:

E.g. publication of statistical divisions, reports of ministries of finance, food and agriculture, planning and development etc.

2.                 Semi official sources:

E.g. publication of state bank, wapda, P.I.A local bodies etc.

3.                 Private sources:

E.g. publication of state association, chambers of commerce and industry, private commercial and financial institutions etc.

4.                 Research organizations:

E.g. publication of research organizations like universities, institute of education and research etc.