Collection of Data — Economics STD 11 Commerce — Question

Primary data are those which are collected for a specific purpose directly from the field of enquiry, and thus original in nature. The procedure adopted for collection of data may either be complete enumeration or sampling.(i.e. sample survey). Primary data provides a statistician with detailed information. Such data are published by the authorities themselves as Government, Civil bodies, Trade Associations etc. Individuals such as Economists, and institutions like Banks and other allied bodies can collect primary data for a specific purpose, by engaging trained investigators. The collection of primary data is a laborious and time consuming process. It is also expensive. Secondary data are such numerical information which has been already collected by some agency for a specific purpose and are subsequently compiled from that source for application in a different connection. For example the Census figures published will be primary data, whereas the same data reproduced in another publication will come under the category of secondary data. The chief sources of secondary data are: Publications of State Governments, of Foreign governments, and international bodies like ILO, UNO, UNESCO, WHO, etc.
In short, when time and funds are less and accuracy is not so important then secondary method in better, otherwise Primary method in better.