PRIMARY AND SECONDARY DATA

Population research requires diverse kinds of data. They may broadly be divided into two categories of data: primary and secondary. Primary data are those data which are collected by the researchers themselves. Thus the data collected from key informants, survey data, focus group discussions (FGDs), and experimental data – frequently used in action research – are all the types of primary data. Secondary data refer to pre-existing data, collected by other researchers in the past for the similar or different objectives. For example, in situation analysis of HIV/AIDS, results of national and subnational surveys on issues pertaining to reproduction, STI/RTI, mortality and morbidity, administrative records from police and health departments, development data from District Rural Development Authorities (DRDAs), education data from Basic Education Officers, etc. are secondary data. They present a broad scenario of development and HIV/AIDS in the study area.

The secondary data can be of immense use but the problem with secondary data is that those who collected them may have used other definitions of study variables than those used by the researcher. One must know these definitions before using the data. One must also examine the limitations and various kinds of errors that may be present in the data. If you are using census or NSSO data on work and employment you must study the definition of employment and unemployment used by them so that the data can be interpreted accurately. Secondary data has the attraction of being natural, unbiased and non-obtrusive. In sociology class many of my Muslim students claimed that Muslims did not believe in the caste system and the data collected by sociologists of caste, among Muslims, is biased and distorted. I told them to look at matrimonial pages (newspapers and net), and treat them as the secondary source of data. They are written by Muslims themselves and they show that common Muslims (or their parents) are looking for brides and grooms in the same caste. If they are liberal they write “caste no bar”. This shows that caste among Muslims is a social reality.