Question

"Secondary data are those which are already in existence, and which have been collected, for some other purpose than the answering of the question in hand". Substantiate this statement focusing on the difference between primary and secondary data.

Answer 1

PRIMARY DATA -the source of the first hand or primary data is through sample and population . The several methods like surveys , interviews , or experiments , observations  are carried out . The object is to understand the specific issue regarding literacy , education , health , demography , sex ratio etc .
Secondary data - the data which has already been collected and is readily available . this the cheapest method of data collection . This method is used to increase the sampling size of research studies .