Elementary Statstics

2.1.12 Sources of secondary data

In most of the studies the investigator may find it difficult to collect primary data on all related issues and as such he makes use of the data collected by others. There is a vast amount of published information from which statistical studies may be made and fresh statistics are constantly in a state of production. The sources of secondary data can broadly be classified under two heads:

(1) Published sources, and (2) Unpublished sources